c. 1300, "lost, ruined, undone" (now archaic), from Old English loren, strong past participle of leosan "to lose" (from Proto-Germanic *lausa-, from PIE root *leu- "to loosen, divide, cut apart"). Meaning "abandoned, left alone, lonely" is from late 15c. Compare forlorn. Old English leosan became Middle English lesen, which begat losel, an old word for "a good-for-nothing fellow" (mid-14c.); hence loselry.