D defs.my
Entry 2 senses Webster, 1913

efficience

/(ĕf*fĭsh"ens)/ · ef·fi·cience · IPA
01 n. The quality of being efficient or producing an effect or effects; efficient power; effectual agency.
  1. 1.
    The quality of being efficient or producing an effect or effects; efficient power; effectual agency.
    “The manner of this divine efficiency being far above us.” Hooker.
  2. 2.
    The ratio of useful work to energy expended.(Mech.)
Phrases & compounds
efficiency of a heat engine — the ratio of the work done by an engine, to the work due to the heat supplied to it.