Entry 1 sense Webster, 1913 Flotsam /flät'-səm/ · Flot·sam · IPA /ˈflɑtsəm/ 01 n. Goods lost by shipwreck, and floating on the sea; -- in distinction from jetsam or jetson. 1. Goods lost by shipwreck, and floating on the sea; -- in distinction from jetsam or jetson.(Law)