profitable (adj.)

early 14c., profilen (transitive), "to advance, benefit, gain," from profit (n.) and from Old French prufiter, porfiter "to benefit," from prufit. From mid-14c. as "be helpful or useful, do good." Intransitive sense of "gain in a material sense, derive profit or benefit" is from c. 1400. Related: Profited; profiting.

mid-14c., profitabilite, "usefulness, use," from profitable + -ity or from Old French profitablete. Sense of "quality of being profitable, gainfulness" is by 1890.