basis

American  

[bey-sis] / ˈbeɪ sɪs /

noun

bases plural

1. the bottom or base of anything; the part on which something stands or rests.

2. anything upon which something is based; fundamental principle; groundwork.

3. the principal constituent; fundamental ingredient.

4. a basic fact, amount, standard, etc., used in making computations, reaching conclusions, or the like.

   The nurse is paid on an hourly basis. He was chosen on the basis of his college grades.

5. Mathematics. a set of linearly independent elements of a given vector space having the property that every element of the space can be written as a linear combination of the elements of the set.

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basis British  

/ ˈbeɪsɪs /

noun

1. something that underlies, supports, or is essential to something else, esp an abstract idea

2. a principle on which something depends or from which something has issued

3. maths (of a vector space) a maximal set of linearly independent vectors, in terms of which all the elements of the space are uniquely expressible, and the number of which is the dimension of the space

   the vectors x, y and z form a basis of the 3-dimensional space all members of which can be written as ax + by + cz

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basis Scientific  

/ bā′sĭs /

bases plural

1. A set of independent vectors whose linear combinations define a vector space, such as a reference frame used to establish a coordinate system.

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basis Idioms  

1. see on a first-name basis.

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Usage

Plural word for basis The plural form of basis is bases, pronounced [ bey-seez ]. The plurals of several other singular words that end in -is are also formed in this way, including hypothesis/hypotheses, crisis/crises, and axis/axes. A similar change is made when pluralizing appendix as appendices. Irregular plurals that are formed like bases derive directly from their original pluralization in Latin and Greek.

Synonym Usage

See base ¹.

Other Word Forms

Noun Inflected Forms

• bases
  plural

Etymology

Origin of basis

First recorded in 1525–35; from Latin, from Greek básis “step, place one stands on, pedestal,” from ba(ínein) “to walk, step” ( see also come) + -sis -sis; cf. base ¹

Explanation

Basis is the underlying reason or assumption. The basis of a dictionary is that people are curious to learn the meanings of new words. You are interested, right? Basis can also apply to a system or pattern that has been established. For example: Since your job is so exhausting, you need vacations on a regular basis. The basis of democracy is regular free elections. Not surprisingly, as its sense of something from which other things spring, basis comes from the Latin word of the same spelling meaning "foundation."

Example Sentences

See Examples For:

basis bases

Once ready, it is available on a "pay what you feel, pay what you can afford" basis and all stays within the community.

From BBC ● Jul. 19, 2026

The agency’s chairman Brendan Carr said the commission will consider TV station mergers that exceed the current ownership limits on a “case by case” basis.

From Los Angeles Times ● Jul. 19, 2026

And yet, Nolan returned to Homer’s poem, the structural basis of almost all storytelling throughout human record, which, if you break it down more acutely, includes Nolan’s filmography.

From Salon ● Jul. 18, 2026

“You might be able to make some, but can you make it on a consistent basis with good yields? That’s when the experience comes in,” he said.

From MarketWatch ● Jul. 18, 2026

Equal temperament has a clear scientific/mathematical basis, is very straightforward, does not require retuning for key changes, and is unquestioningly accepted by most people.

From "Understanding Basic Music Theory" by Catherine Schmidt-Jones and Russel Jones

The Coast Guard already bases ships in Guam and Hawaii, including what it calls an Indo-Pacific support cutter.

From The Wall Street Journal ● Jul. 15, 2026

Starship's enormous payload capacity and planned rapid reuse make it well suited for ambitious projects such as lunar bases, Mars missions, and massive satellite constellations.

From Science Daily ● Jul. 11, 2026

Bottom line: You did the right thing by seeking a second opinion and, just to cover your bases, a third opinion, too.

From MarketWatch ● Jul. 10, 2026

The slider he dealt two batters later to second baseman Edouard Julien also crossed the zone too far over the plate, and Julien rounded the bases with another homer.

From Los Angeles Times ● Jul. 9, 2026

I used blue painter’s tape for the diamond, flattened shoebox tops for the bases, and a balance ball for the pitcher’s mound.

From "A High Five for Glenn Burke" by Phil Bildner

Related Words

• assumption
• base
• essential
• evidence
• explanation
• footing
• fundamental
• justification
• premise
• principle
• proof
• reason
• security
• support
• theory