Emily Dickinson Lexicon

JET'SAM, or JET'SON, n. [or JET'TI-SON; Fr. jetter, to throw.]

In law and commerce, properly, the throwing of goods overboard in order to lighten a ship in a tempest for her preservation. The word may however be used for the goods thus thrown away, or adverbially. Jetsam, is where goods are cast into the sea, and there sink and remain under water; flotsam, is where they continue swimming; flotsam, is where they are sunk in the sea, but tied to a cork or buoy. – Park. Blackstone.