"gain in money or goods, profit," late 14c., from Old French lucre, from Latin lucrum "material gain, advantage, profit; wealth, riches," of uncertain origin. De Vaan says from Proto-Italic *lukro-, from PIE *lhu-tlo- "seizure, gain," with cognates in Greek apolauo "take hold of, enjoy," leia (Doric laia) "booty;" Gothic laun "reward."
Often specifically in a restricted sense of "base or unworthy gain, money or wealth as the object of greed," hence "greed." Filthy lucre (Titus i.11) is Tyndale's rendering of Greek aiskhron kerdos.
"yielding gain, highly profitable," early 15c., from Old French lucratif "profitable" and directly from Latin lucrativus "gainful, profitable," from lucratus, past participle of lucrari "to gain, win, acquire," from lucrum "gain, profit" (see lucre). Related: Lucratively; lucrativeness.