n.
Pronunciation: i- ' fi-sh ə n-s ē
Function: noun
Inflected Form: plural -cies
Date: 1633
1 : the quality or degree of being efficient
2 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 it
3 : EFFICIENCY APARTMENT