TRAN'SOM, noun [Latin transenna, from trans, over, across.] 1. A beam or timber extended across the stern-post of a ship, to strengthen the aft-part and give it due form. 2. In architecture, the piece that is framed across a double light window; or a lintel over a door; the vane of a cross-staff.
Source: Webster's 1828 American Dictionary ↗ · public-domain · returned verbatim, no AI