co·ef·fi·cient 
/ˌkowəˈfɪʃənt/ noun
plural co·ef·fi·cients /ˌkowəˈfɪʃənt/ noun [count] 1 mathematics : a number by which another number or symbol is multiplied
▪ 5 is the coefficient of y in the term 5y. 2 physics : a number that is used to measure some property or characteristic of a substance
▪ a coefficient of friction ▪ the metal's coefficient of expansion
▪ 5 is the coefficient of y in the term 5y.
▪ a coefficient of friction ▪ the metal's coefficient of expansion
