basis

American  

[bey-sis] / ˈbeɪ sɪs /

noun

plural

bases

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 /

plural

bases

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.

Related Words

See base ¹.

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” ( come ) + -sis -sis; 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

The facility also would serve about 1,000 people on an outpatient basis.

From Los Angeles Times • Apr. 13, 2026

Matejka and team acknowledge inflation may increase perhaps 1.5 percentage points on a year-over-year basis but central banks are likely to look through this.

From MarketWatch • Apr. 13, 2026

The two-year Treasury yield was up 3.4 basis points at 3.833%, the 10-year yield rose 3 bps to 4.346% and the 30-year was up 2.3 bps at 4.936%.

From The Wall Street Journal • Apr. 13, 2026

It could not be credibly disputed on the basis of the statistics if he draws level with or eclipses Vardon.

From BBC • Apr. 13, 2026

So, decisions about the existence of a vacuum should be made not by appeal to authority but on the basis of sense experience and reason.

From "The Invention of Science" by David Wootton

Related Words

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