1570, alteration of M.E. jetteson "act of throwing goods overboard to lighten a ship," from Anglo-Fr. getteson (see jettison). Form perhaps influenced by flotsam. For distinction of meaning, see flotsam.
Main Entry: jet·sam Pronunciation: 'jet-s&m Function: noun : the part of a ship, its equipment, or its cargo that is cast overboard to lighten the load in time of distress and that sinks or is washed ashore —compare FLOTSAM