Entry 1 sense Webster, 1913 Ligan /(lī"gan)/ · Li·gan · IPA 01 n. Goods sunk in the sea, with a buoy attached in order that they may be found again. See Jetsam and Flotsam. 1. Goods sunk in the sea, with a buoy attached in order that they may be found again. See Jetsam and Flotsam.(Law) See: Jetsam, Flotsam