[ beys ]
See synonyms for: basebasedbaserbasest on

  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.

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

  2. Architecture.

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

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

  3. Botany, Zoology.

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

    • the point of attachment.

  4. the principal element or ingredient of anything, considered as its fundamental part: face cream with a lanolin base;paint with a lead base.

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

  6. the main supporters or fans of a political candidate, celebrity, company, etc.: Her proposed policies are calculated to appeal to her base.

  7. Baseball.

    • any of the four corners of the diamond, especially first, second, or third base.: Compare home plate.

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

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

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

  10. Military.

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

    • a supply installation for a large military force.

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

  12. Mathematics.

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

    • 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.

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

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

  13. Also called base line. Surveying. See under triangulation (def. 1).

  14. Painting.

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

  15. 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.

  16. Chemistry.

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

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

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

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

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

  17. 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.: Compare root1 (def. 12), stem1 (def. 16).

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

  19. Electronics.

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

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

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

  21. Heraldry. the lower part of an escutcheon.

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

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

  1. serving as or forming a base: The walls will need a base coat and two finishing coats.

verb (used with object),based, bas·ing.
  1. to make or form a base or foundation for.

  2. to establish, as a fact or conclusion (usually followed by on or upon): He based his assumption of her guilt on the fact that she had no alibi.

  1. to place or establish on a base or basis; ground; found (usually followed by on or upon): Our plan is based on a rising economy.

  2. to station, place, or situate (usually followed by at or on): He is based at Fort Benning. The squadron is based on a carrier.

verb (used without object),based, bas·ing.
  1. to have a basis; be based (usually followed by on or upon): 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 about base

  1. get to first base. first base (def. 2).

  2. off base,

    • Baseball. not touching a base: The pitcher caught him off base and, after a quick throw, he was put out by the second baseman.

    • Informal. badly mistaken: The police were way off base when they tried to accuse her of the theft.

  1. on base, Baseball. having reached a base or bases: Two men are on base.

  2. touch base. See entry at touch base.

Origin of base

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

synonym study For base

1. 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.

Other definitions for base (2 of 2)

[ beys ]

adjective,bas·er, bas·est.
  1. morally low; without estimable personal qualities; dishonorable; meanspirited; selfish; cowardly.

  2. of little or no value; worthless: hastily composed of base materials.

  1. debased or counterfeit: an attempt to eliminate the base coinage.

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

  3. of illegitimate birth.

  4. not classical or refined: base language.

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

  6. Archaic.

    • of humble origin or station.

    • of small height.

    • low in place, position, or degree: base servitude.

  7. Obsolete. deep or grave in sound; bass: the base tones of a piano.

  1. Music Obsolete. bass1 (defs. 3, 4).

Origin of base

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

synonym study For base

1. See mean2.

Other words for base

Other words from base

  • base·ly, adverb
  • base·ness, noun Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use base in a sentence

  • The two British matrons, therefore, spoke the prejudice of the better rather than the baser class.

    Lazarre | Mary Hartwell Catherwood
  • The pity that a man should be capable of so exposing his baser self struck me in the midst of all my indignation.

British Dictionary definitions for base (1 of 2)


/ (beɪs) /

  1. the bottom or supporting part of anything

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

    • a centre of operations, organization, or supply: the climbers made a base at 8000 feet

    • (as modifier): base camp

  1. a centre from which military activities are coordinated

  2. 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

  3. the main ingredient of a mixture: to use rice as a base in cookery

  4. 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

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

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

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

  8. biology

    • the part of an organ nearest to its point of attachment

    • the point of attachment of an organ or part

  9. the bottommost layer or part of anything

  10. architect

    • the lowest division of a building or structure

    • the lower part of a column or pier

  11. another word for baseline (def. 2)

  12. the lower side or face of a geometric construction

  13. maths

    • the number of distinct single-digit numbers in a counting system, and so the number represented as 10 in a place-value system: the binary system has two digits, 0 and 1, and 10 to base two represents 2 See place-value

    • (of a logarithm or exponential) the number whose powers are expressed: since 1000 = 10³, the logarithm of 1000 to base 10 is 3

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

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

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

  15. linguistics

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

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

  18. heraldry the lower part of the shield

  19. jewellery the quality factor used in pricing natural pearls

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

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

  22. the main source of a certain commodity or element: a customer base; their fan base

  23. get to first base US and Canadian informal to accomplish the first stage in a project or a series of objectives

  24. off base US and Canadian informal wrong or badly mistaken

  25. touch base to make contact

  1. (tr foll by on or upon) to use as a basis (for); found (on): your criticisms are based on ignorance

  2. (often foll by at or in) to station, post, or place (a person or oneself)

Origin of base

C14: from Old French, from Latin basis pedestal; see basis

British Dictionary definitions for base (2 of 2)


/ (beɪs) /

  1. devoid of honour or morality; ignoble; contemptible

  2. of inferior quality or value

  1. debased; alloyed; counterfeit: base currency

  2. English history

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

    • holding land by villein or other ignoble service

  3. archaic born of humble parents; plebeian

  4. archaic illegitimate

adjective, noun
  1. music an obsolete spelling of bass 1

Origin of base

C14: from Old French bas, from Late Latin bassus of low height, perhaps from Greek bassōn deeper

Derived forms of base

  • basely, adverb
  • baseness, noun

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Scientific definitions for base


[ bās ]

    • 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. Compare acid.

    • : See nitrogen base.

    • 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.

    • 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.

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

The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

Cultural definitions for base


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.

The New Dictionary of Cultural Literacy, Third Edition Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

Other Idioms and Phrases with base


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

The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.