Word Origin & History
c.1600, from Anglo-Fr. floteson, from O.Fr. flotaison "a floating," from floter "to float" (of Gmc. origin) + -aison, from L. -ation(em). Spelled flotsen till mid-19c. when it altered, perhaps under influence of many English words in -some. In British law, flotsam are goods found floating on the sea
as a consequence of a shipwreck or action of wind or waves; jetsam are things cast out of a ship in danger of being wrecked, and afterward washed ashore, or things cast ashore by the sailors. Whatever sinks is lagan.