Meaning

adjective being effective without wasting time or effort or expense

adjective able to accomplish a purpose; functioning effectively; -G.B.Shaw

origin1398, “making,” from Old French, from Latin efficientem, nominative efficiēns, participle of efficere (“work out, accomplish”) (see effect). Meaning “productive, skilled” is from 1787. Efficiency apartment is first recorded 1930, American English.

Etymology from Wiktionary, CC BY-SA 3.0