Quiz: Remember the definition of mal de mer?
1520s, "overthrown, routed" (now obsolete in this sense), from Latin profligatus "destroyed, ruined, corrupt, abandoned, dissolute," past participle of profligare "to cast down, defeat, ruin," from pro- "down, forth" (see pro-) + fligere "to strike" (see afflict). Main modern meaning "recklessly extravagant" is 1779, via notion of "ruined by vice" (1640s, implied in a use of profligation). Related: Profligately. As a noun from 1709.