base

¹ American  

[beys] / beɪs /

noun

1. the bottom support of anything; that on which a thing stands or rests.

   a metal base for the table.

2. a fundamental principle or groundwork; foundation; basis.

   the base of needed reforms.

3. the bottom layer or coating, as of makeup or paint.

4. Architecture.

   1. the distinctively treated portion of a column or pier below the shaft or shafts.

   2. the distinctively treated lowermost portion of any construction, as a monument, exterior wall, etc.

5. Botany, Zoology.

   1. the part of an organ nearest its point of attachment.

   2. the point of attachment.

6. the principal element or ingredient of anything, considered as its fundamental part.

   face cream with a lanolin base;

   paint with a lead base.

7. that from which a commencement, as of action or reckoning, is made; a starting point or point of departure.

8. the main supporters or fans of a political candidate, celebrity, company, etc..

   Her proposed policies are calculated to appeal to her base.

9. Baseball.

   1. any of the four corners of the diamond, especially first, second, or third base.

   2. a square canvas sack containing sawdust or some other light material, for marking first, second, or third base.

10. a starting line or point for runners, racing cars, etc.

11. (in hockey and other games) the goal.

12. Military.

    1. a fortified or more or less protected area or place from which the operations of an army or an air force proceed.

    2. a supply installation for a large military force.

13. Geometry. the line or surface forming the part of a figure that is most nearly horizontal or on which it is supposed to stand.

14. Mathematics.

    1. the number that serves as a starting point for a logarithmic or other numerical system.

    2. a collection of subsets of a topological space having the property that every open set in the given topology can be written as the union of sets of the collection.

    3. a collection of neighborhoods of a point such that every neighborhood of the point contains one from the collection.

    4. a collection of sets of a given filter such that every set in the filter is contained in some set in the collection.

15. Also called base line.  Surveying. triangulation1

16. Painting.

    1. vehicle.

    2. Also called carrier.  inert matter, used in the preparation of lakes, onto which a coloring compound is precipitated.

17. Photography. a thin, flexible layer of cellulose triacetate or similar material that holds the light-sensitive film emulsion and other coatings, especially on motion-picture film.

18. Chemistry.

    1. a compound that reacts with an acid to form a salt, as ammonia, calcium hydroxide, or certain nitrogen-containing organic compounds.

    2. the hydroxide of a metal or of an electropositive element or group.

    3. a group or molecule that takes up or accepts protons.

    4. a molecule or ion containing an atom with a free pair of electrons that can be donated to an acid; an electron-pair donor.

    5. any of the purine and pyrimidine compounds found in nucleic acids: the purines adenine and guanine and the pyrimidines cytosine, thymine, and uracil.

19. Grammar. the part of a complex word, consisting of one or more morphemes, to which derivational or inflectional affixes may be added, as want in unwanted or biolog- in biological.

20. Linguistics. the component of a generative grammar containing the lexicon and phrase-structure rules that generate the deep structure of sentences.

21. Electronics.

    1. an electrode or terminal on a transistor other than the emitter or collector electrodes or terminals.

    2. the part of an incandescent lamp or electron tube that includes the terminals for making electrical connection to a circuit or power supply.

22. Stock Exchange. the level at which a security ceases a decline in price.

23. Heraldry. the lower part of an escutcheon.

24. Armor. bases, a tonlet formed of two shaped steel plates assembled side by side.

25. Jewelry. pavilion.

26. Heraldry. in base, in the lower part of an escutcheon.

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adjective

• baser,
  comparative
• basest
  superlative

1. serving as or forming a base.

   The walls will need a base coat and two finishing coats.

verb (used with object)

• bases,
  present (3rd person singular)
• based,
  past participle,  past
• basing
  present participle

1. to make or form a base or foundation for.

2. to establish, as a fact or conclusion (usually followed by on orupon ).

   He based his assumption of her guilt on the fact that she had no alibi.

3. to place or establish on a base or basis; ground; found (usually followed by on orupon ).

   Our plan is based on a rising economy.

4. to station, place, or situate (usually followed by at oron ).

   He is based at Fort Benning. The squadron is based on a carrier.

verb (used without object)

• bases,
  present (3rd person singular)
• based,
  past participle,  past
• basing
  present participle

1. to have a basis; be based (usually followed by on orupon ).

   Fluctuating prices usually base on a fickle public's demand.

2. to have or maintain a base.

   I believe they had based on Greenland at one time.

idioms

1. get to first base. first base.

2. on base, having reached a base or bases.

   Two men are on base.

3. touch base. see touch base.

4. off base,

   1. Baseball. not touching a base.

      The pitcher caught him off base and, after a quick throw, he was put out by the second baseman.

   2. Informal. badly mistaken.

      The police were way off base when they tried to accuse her of the theft.

base ² American  

[beys] / beɪs /

adjective

• baser,
  comparative
• basest
  superlative

1. morally low; without estimable personal qualities; dishonorable; meanspirited; selfish; cowardly.

   Synonyms:

   contemptible, despicable

2. of little or no value; worthless.

   hastily composed of base materials.

   Synonyms:

   tawdry, cheap, inferior, poor

3. debased or counterfeit.

   an attempt to eliminate the base coinage.

   Synonyms:

   spurious, fake

4. characteristic of or befitting an inferior person or thing.

   Synonyms:

   menial, lowly, ignoble, humble

5. of illegitimate birth.

6. not classical or refined.

   base language.

7. Old English Law. held by tenure less than freehold in return for a service viewed as somewhat demeaning to the tenant.

8. Archaic.

   1. of humble origin or station.

   2. of small height.

   3. low in place, position, or degree.

      base servitude.

9. Obsolete. deep or grave in sound; bass.

   the base tones of a piano.

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noun

1. Music Obsolete. bass.

base ¹ British  

/ beɪs /

noun

1. the bottom or supporting part of anything

2. the fundamental or underlying principle or part, as of an idea, system, or organization; basis

3. 1. a centre of operations, organization, or supply

      the climbers made a base at 8000 feet

   2. ( as modifier )

      base camp

4. a centre from which military activities are coordinated

5. anything from which a process, as of measurement, action, or thought, is or may be begun; starting point

   the new discovery became the base for further research

6. the main ingredient of a mixture

   to use rice as a base in cookery

7. a chemical compound that combines with an acid to form a salt and water. A solution of a base in water turns litmus paper blue, produces hydroxyl ions, and has a pH greater than 7. Bases are metal oxides or hydroxides or amines See also Lewis base

8. biochem any of the nitrogen-containing constituents of nucleic acids: adenine, thymine (in DNA), uracil (in RNA), guanine, or cytosine

9. a medium such as oil or water in which the pigment is dispersed in paints, inks, etc; vehicle

10. the inorganic material on which the dye is absorbed in lake pigments; carrier

11. biology

    1. the part of an organ nearest to its point of attachment

    2. the point of attachment of an organ or part

12. the bottommost layer or part of anything

13. architect

    1. the lowest division of a building or structure

    2. the lower part of a column or pier

14. another word for baseline

15. the lower side or face of a geometric construction

16. maths

    1. the number of distinct single-digit numbers in a counting system, and so the number represented as 10 in a place-value system See place-value

       the binary system has two digits, 0 and 1, and 10 to base two represents 2

    2. (of a logarithm or exponential) the number whose powers are expressed

       since 1000 = 10³, the logarithm of 1000 to base 10 is 3

    3. (of a mathematical structure) a substructure from which the given system can be generated

    4. the initial instance from which a generalization is proven by mathematical induction

17. Also called: base clause.  logic maths the initial element of a recursive definition, that defines the first element of the infinite sequence generated thereby

18. linguistics

    1. a root or stem

    2. See base component

19. electronics the region in a transistor between the emitter and collector

20. photog the glass, paper, or cellulose-ester film that supports the sensitized emulsion with which it is coated

21. heraldry the lower part of the shield

22. jewellery the quality factor used in pricing natural pearls

23. a starting or finishing point in any of various games

24. baseball any of the four corners of the diamond, which runners have to reach in order to score

25. the main source of a certain commodity or element

    a customer base

    their fan base

26. informal to accomplish the first stage in a project or a series of objectives

27. informal wrong or badly mistaken

28. to make contact

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verb

1. (tr foll by on or upon) to use as a basis (for); found (on)

   your criticisms are based on ignorance

2. to station, post, or place (a person or oneself)

base ² British  

/ beɪs /

adjective

1. devoid of honour or morality; ignoble; contemptible

2. of inferior quality or value

3. debased; alloyed; counterfeit

   base currency

4. English history

   1. (of land tenure) held by villein or other ignoble service

   2. holding land by villein or other ignoble service

5. archaic born of humble parents; plebeian

6. archaic illegitimate

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adjective

1. music an obsolete spelling of bass 1

base Scientific  

/ bās /

1. Chemistry

   1. Any of a class of compounds that form hydroxyl ions (OH) when dissolved in water, and whose aqueous solutions react with acids to form salts. Bases turn red litmus paper blue and have a pH greater than 7. Their aqueous solutions have a bitter taste.

   2. See nitrogen base

2. Mathematics

   1. The side or face of a geometric figure to which an altitude is or is thought to be drawn. The base can be, but is not always, the bottom part of the figure.

   2. The number that is raised to various powers to generate the principal counting units of a number system. The base of the decimal system, for example, is 10.

   3. The number that is raised to a particular power in a given mathematical expression. In the expression a ⁿ , a is the base.

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base Cultural  

1. Any of a number of bitter-tasting, caustic materials. Technically, a material that produces negative ions in solution. A base is the opposite of an acid and has a pH of 7 to 14. A given amount of a base added to the same amount of an acid neutralizes the acid; water and a salt are produced. Alkalis are bases; ammonia is a common base.

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base More Idioms  

1. see get to first base; off base; touch base.

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Synonym Usage

Base, basis, foundation refer to anything upon which a structure is built and upon which it rests. Base usually refers to a literal supporting structure: the base of a statue. Basis more often refers to a figurative support: the basis of a report. Foundation implies a solid, secure understructure: the foundation of a skyscraper or a rumor.

See mean ².

Other Word Forms

Derived Forms

• baseness
  noun
• basely
  adverb

Inflected Forms

Adjectives

• baser
  comparative
• basest
  superlative

Participles

• basing
  present
• based
  past

Conjugated Forms

Present

• base
  simple
• bases
  simple
• have based
  perfect
• has based
  perfect
• am basing
  progressive
• are basing
  progressive
• is basing
  progressive
• have been basing
  perfect progressive
• has been basing
  perfect progressive

Past

• based
  simple
• had based
  perfect
• was basing
  progressive
• were basing
  progressive
• had been basing
  perfect progressive

Future

• will base
  simple
• will have based
  perfect
• will be basing
  progressive
• will have been basing
  perfect progressive

Etymology

Origin of base¹

First recorded in 1275–1325; Middle English noun base, bas, bace, from Old French base, basse, from Latin basis basis

Origin of base²

First recorded in 1350–1400; Middle English bas, from Old French, from Late Latin bassus “low, short,” perhaps of Oscan origin

Explanation

The base of something is usually the foundation, starting point, or main ingredient of something. A soup base is the flavoring or broth you use to get your soup started. If you're a soldier, you might live on a base ("place where you're stationed"). When your unit plays softball, you must touch each base before scoring. The bottom of pentagon-shaped home plate is its base ("bottom"). Yelling at or pushing the umpire is considered base ("mean-spirited") behavior. At end of the season, your team might get a trophy, which sits on a base ("pedestal"), or a plaque made of brass, an alloy of zinc, which is base metal (it corrodes easily).

Example Sentences

See Examples For:

base baser basest bases based basing

The dead and missing were soldiers serving at the base, the defense ministry said.

From Barron's ● Sep. 5, 2026

Friedkin is head of The Friedkin Group, which runs the club from its base in Houston, but has not attended a home game since completing a takeover of the club in December 2024.

From BBC ● Sep. 5, 2026

The images showed that RNA polymerase identifies the synthetic DNA letters using many of the same biochemical and structural signals it relies on to recognize natural base pairs.

From Science Daily ● Sep. 5, 2026

Firstly, metallurgical testwork returned materially higher recoveries of precious and base metals than previously assumed in an April scoping study.

From The Wall Street Journal ● Sep. 4, 2026

Like me, she wore an elaborate dress trimmed with lace and her hair was twisted back into a knot at the base of her neck.

From "Glitch" by Laura Martin

There may be a baser motive at play: money.

From Slate ● Sep. 4, 2026

But it can also enhance our baser instincts.

From The Wall Street Journal ● May 8, 2026

But it also quite consciously plays to the baser side of us that takes cold comfort, even joy, at the miseries of the hyperwealthy.

From Salon ● Mar. 14, 2026

“The Killer” should satisfy those with baser instincts, particularly as it reunites Fincher with “Seven” screenwriter Andrew Kevin Walker, who adapted Alexis Nolent’s noirish graphic novel.

From Los Angeles Times ● Aug. 30, 2023

And it seemed to Tyrion that the gold and silver and platinum links far outnumbered those of baser metals.

From "A Clash of Kings" by George R.R. Martin

But the effect on most of its victims was to bring out their basest instincts.

From The Wall Street Journal ● May 29, 2026

Detractors said the app catered to the basest human interests — celebrity gossip, scandal, disaster and violence — to keep users hooked as long as possible.

From New York Times ● Dec. 20, 2022

They prefer stuff like "Warrior Poet Society," because it flatters their basest instincts.

From Salon ● Apr. 29, 2022

Variety calls the film, the debut feature from writer-director Wyatt Rockefeller, a “stark, scorched, occasionally jolting sci-fi slow burn in which relocating to the Red Planet can’t save humanity from its basest instincts.”

From Washington Post ● Jul. 21, 2021

It WAS basest betrayal to think of anything but Theresa, but they had no choice.

From "Typical American" by Gish Jen

On an adjacent island facing Setouchi are small disused bases that launched shinyo suicide motorboat attacks on Allied forces in World War II.

From The Wall Street Journal ● Sep. 3, 2026

The two "agreed to accelerate force posture initiatives at Australian bases, bolster cooperation in combined logistics, and build greater interoperability through joint exercises," the Pentagon said.

From Barron's ● Sep. 3, 2026

He drove in another run in the ninth, grounding into a fielder’s choice with the bases loaded, as part of a three-run last-ditch rally.

From Los Angeles Times ● Sep. 2, 2026

According to Unifil, the Israeli military has established four new bases in the invaded areas, bringing the number of such positions to nine.

From BBC ● Sep. 2, 2026

A buzzer sounded at over two hundred bases, alerting personnel that the commander was on the line.

From "Fallout: Spies, Superbombs, and the Ultimate Cold War Showdown" by Steve Sheinkin

These signs include an opaque ownership structure of a firm based in the U.A.E. or a company registered in Hong Kong that uses a Chinese bank account and has no online presence.

From The Wall Street Journal ● Sep. 6, 2026

Tielemans' pre-season appearances seemed to be based around developing an understanding with skipper Fernandes.

From BBC ● Sep. 5, 2026

Brown, based in Seattle, said the chat took place at 6 p.m. his time, which would have meant the recruiter was working at 9 p.m. their time.

From MarketWatch ● Sep. 5, 2026

Instead, a single-particle model based on a three-dimensional Dirac Hamiltonian and including strong spin-orbit coupling was able to reproduce the experimental regimes.

From Science Daily ● Sep. 5, 2026

“It’s an arts and entertainment podcast based in Chicago,” Camille says.

From "South of Somewhere" by Kalena Miller

The country is also a source of funds for investment in sectors like artificial intelligence and gives the U.S. military important basing rights.

From The Wall Street Journal ● Aug. 27, 2026

The point of these various studies is not that we should start basing our investment decisions on weather reports or the phases of the moon.

From MarketWatch ● Aug. 12, 2026

La Guaira's Governor Jose Alejandro Teran, however, last week said 1,338 people were missing, basing the count on a residential registry.

From Barron's ● Aug. 6, 2026

The U.S. military first secured basing rights in the kingdom in 1945 and expanded them during the wars with Iraq.

From The Wall Street Journal ● Jul. 1, 2026

Articles accused their detractors of basing comments on brief medical bulletins and newspaper reports, hardly enough to make a diagnosis.

From "Ambushed!" by Gail Jarrow

Related Words

• camp
• center
• depot
• field
• garrison
• home
• port
• post
• settlement
• site
• station
• terminal