coefficient

noun

co·​ef·​fi·​cient ˌkō-ə-ˈfi-shənt 

1

: any of the factors of a product considered in relation to a specific factor

especially : a constant factor of a term as distinguished from a variable

2

a

: a number that serves as a measure of some property or characteristic (as of a substance, device, or process)

coefficient of expansion of a metal

b

: measure

Examples of coefficient in a Sentence

5 is the coefficient of y in the term 5y.

the metal's coefficient of expansion

Recent Examples on the Web

By plotting the coefficients of the polynomial as a sort of heat map, the researchers have created striking visuals — an ornate hexagonal QR code for each knot. —Erica Klarreich, Quanta Magazine, 22 Apr. 2026

Howe’s side must rely on coefficients and how other sides fare in the FA Cup but theoretically, Europe is there for the taking. —George Caulkin, New York Times, 22 Mar. 2026

The final participants are divided into four pots of nine each based on the coefficient ranking system. —Encyclopedia Britannica, 20 Mar. 2026

As an example, when two steel surfaces interact (like a train car wheel on a track), the coefficient of static friction would be 0.74, but the coefficient of kinetic friction would be 0.57. —Rhett Allain, Wired News, 10 Mar. 2026

Word History

Etymology

New Latin coefficient-, coefficiens, from Latin co- + efficient-, efficiens efficient

First Known Use

1708, in the meaning defined at sense 1

Phrases Containing coefficient

• binomial coefficient
• coefficient of correlation
• coefficient of viscosity
• correlation coefficient
• drag coefficient
• extinction coefficient

Rhymes for coefficient

• deficient
• efficient
• omniscient
• proficient
• sufficient
• beneficent
• inefficient
• insufficient

Kids Definition

coefficient

noun

co·​ef·​fi·​cient ˌkō-ə-ˈfish-ənt 

1

: a number or symbol by which another number or symbol (as a mathematical variable) is multiplied

3 is the coefficient of x in the expression 3x

2

: a number that serves as a measure of some property (as of a substance or device)

the metal's coefficient of expansion

Medical Definition

coefficient

noun

co·​ef·​fi·​cient ˌkō-ə-ˈfish-ənt 

: a number that serves as a measure of some property (as of a substance) or characteristic (as of a device or process) and that is commonly used as a factor in computations

the coefficient of expansion of a metal

see absorption coefficient