tran·som / ˈtransəm/ • n. the flat surface forming the stern of a vessel. ∎  a horizontal beam reinforcing the stern of a vessel. ∎  a strengthening crossbar, in particular one set above a window or door. Compare with mullion. ∎ short for transom window.PHRASES: over the transom inf. offered or sent without prior agreement; unsolicited: the editors receive about ten manuscripts a week over the transom.DERIVATIVES: tran·somed adj.

transom cross-beam, esp. spanning an opening. XIV. ME. traversayn, transyn, -ing — (O)F. traversin in same sense, f. traverse TRAVERSE.