tran·som

[tran-suhm]

–noun
1. a crosspiece separating a door or the like from a window or fanlight above it
2. (Also called transom light, transom window) a window above such a crosspiece
3. a crossbar of wood or stone, dividing a window horizontally
4. a window so divided
5. Nautical:

a. a flat termination to a stern, above the water line.
b. framework running athwartships in way of the sternpost of a steel or iron vessel, used as a support for the frames of the counter

6. Artillery: a metal piece connecting the sidepieces of the tail or the cheeks of a gun carriage