noun - Jetsam is (1) equipment or cargo thrown overboard to lighten a ship in distress, (2) discarded cargo or equipment found washed ashore, or (3) discarded odds and ends.
The swimmer ran into jetsam that startled her during the race.
From earlier jetson, alteration of Middle English jetteson, a throwing overboard; see jettison.
Jetsam versus Flotsam
In maritime law, flotsam applies to wreckage or cargo left floating on the sea after a shipwreck. Jetsam applies to cargo or equipment thrown overboard from a ship in distress and either sunk or washed ashore. The common phrase Flotsam and jetsam is now used loosely to describe any objects found floating or washed ashore.