overboard (adv.)

"over the side of a ship," late Old English, from the phrase ofor bord, from over + bord "side of a ship" (see board (n.2)). To throw (something) overboard in the figurative sense of "cast aside, discard, reject" is from 1640s. Figurative sense of "excessively, beyond one's means" (especially in phrase go overboard) is attested by 1931 in Damon Runyon.