Main Entry:

ef·fi·cien·cy

Pronunciation:

\i-ˈfi-shən-sē\

Function:

noun

Inflected Form(s):

plural ef·fi·cien·cies

Date:

1633

1: the quality or degree of being efficient2 a: efficient operation b (1): effective operation as measured by a comparison of production with cost (as in energy, time, and money) (2): the ratio of the useful energy delivered by a dynamic system to the energy supplied to it3: efficiency apartment