n. 1. That which unites in action with something else to produce the same effect. [ 1913 Webster ]
2. [ Cf. F. coefficient. ] (Math.) A number or letter put before a letter or quantity, known or unknown, to show how many times the latter is to be taken; as, 6x; bx; here 6 and b are coefficients of x. [ 1913 Webster ]
3. (Physics) A number, commonly used in computation as a factor, expressing the amount of some change or effect under certain fixed conditions as to temperature, length, volume, etc.; as, the coefficient of expansion; the coefficient of friction. [ 1913 Webster ]
Arbitrary coefficient (Math.), a literal coefficient placed arbitrarily in an algebraic expression, the value of the coefficient being afterwards determined by the conditions of the problem. [ 1913 Webster ]