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

The reactor also possesses a strong negative temperature coefficient, meaning the nuclear reaction naturally slows as temperatures rise, preventing a runaway event. —Aman Tripathi, Interesting Engineering, 6 Nov. 2025

The vehicles may have a lower-than-specified rear brake lining coefficient of friction and could be equipped with a brake vacuum booster without a vacuum sensor, according to the recall report. —James Powel, USA Today, 27 Oct. 2025

The 18 qualified teams were split into pots of three, according to their UEFA coefficient, and were drawn against two teams from each pot, with three matches away and three at home. —Megan Feringa, New York Times, 7 Oct. 2025

According to the International Energy Agency, the coefficient of performance (the ratio of electricity in to heat energy out) is about four, making current models 3 to 5 times more energy efficient than gas boilers. —Sara Kiley Watson, Popular Science, 2 Oct. 2025

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

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

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