basis

American  

[bay-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.

---

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

---

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.

---

basis Idioms  

1. see on a first-name basis.

---

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

U.K. money markets price a 93% probability that the BOE will raise interest rates by 25 basis points on Nov. 5.

From The Wall Street Journal ● Oct. 16, 2026

By the end of the session, it had fallen roughly 10 basis points to 5.09%, its biggest one-day decline in more than a year.

From MarketWatch ● Oct. 16, 2026

But I was interested in the fact that he accumulated so much power, and so that was the basis on which I dug in back in 2022.

From Salon ● Oct. 16, 2026

The Finnish Immigration Service has rejected their asylum request five times, deciding there is "no reasonable basis to believe" the couple would face serious rights violations if returned.

From BBC ● Oct. 16, 2026

But consonance and dissonance do also have a strong physical basis in nature.

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

We certainly didn’t have all those bases covered when we moved to Cuenca, Ecuador, 16 years ago.

From MarketWatch ● Oct. 16, 2026

After World War II, the U.S. increasingly relied on military alliances, overseas bases, trade and international institutions to project power.

From Salon ● Oct. 13, 2026

The Brewers had more than twice as many stolen bases as the Dodgers and more than twice as many sacrifice bunts.

From Los Angeles Times ● Oct. 12, 2026

Military base-related income accounts for around five percent of the region's annual total, and some argue that the bases create jobs.

From Barron's ● Oct. 11, 2026

One lone chemist had suggested, insistently, that the bases of DNA must have something to do with each other.

From "The Gene" by Siddhartha Mukherjee

Random Word

Spin the wheel and learn a new word!

---

Related Words

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

---