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

Example Sentences

The legal basis for the requirement lies in Germany's 1956 Conscription Act, which has been amended several times, most recently last December.

From BBC • Apr. 4, 2026

As of Thursday, the Bloomberg US Treasury Index was down by 2.4% on a total return basis in March.

From Barron's • Apr. 3, 2026

While perhaps the strongest of the three arguments, that title of the Civil Rights Act goes on to require the attorney general to offer a “statement of the basis and the purpose” of their request.

From Salon • Apr. 3, 2026

Deputy Attorney General Todd Blanche will take over on an acting basis.

From The Wall Street Journal • Apr. 2, 2026

The officers had no basis for suspecting Bostick of any criminal activity, but they got lucky.

From "The New Jim Crow" by Michelle Alexander

Related Words

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