"unlooked-for acquisition or good fortune," 1814, originally "a shipwreck" (from the perspective of people living along the coast), from Middle English Godes sonde (c.1200) "God's messenger; what God sends, gift from God, happening caused by God," from God + Middle English sonde "that which is sent, message," from Old English sand, from sendan (see send, v.). General sense is from 1820.