1. The expression of the amount or degree of any quality possessed by a substance, or of the degree of physical or chemical change normally occurring in that substance under stated conditions.

2. The ratio or factor that relates a quantity observed under one set of conditions to that observed under standard conditions, usually when all variables are either 1 or a simple power of 10.

Origin: L. Co-+ efficio (exfacio), to accomplish

(05 Mar 2000)