c.1300, "characterized by vigor or strength; having qualities befitting a knight; valiant, hardy, courageous;" from Old French vertuos "righteous; potent; of good quality; mighty, valiant, brave" (12c.), from Late Latin virtuosus "good, virtuous," from Latin virtus (see virtue). From mid-14c. in English as "having beneficial or efficacious properties;" late 14c. (of persons) as "having excellent moral qualities; conforming to religious law." Related: Virtuously; virtuousness.