a crosspiece separating a door or the like from a window or fanlight above it.

Also called transom light, transom window. a window above such a crosspiece.

a crossbar of wood or stone, dividing a window horizontally.

a window so divided.

Nautical .

a flat termination to a stern, above the water line.

framework running athwartships in way of the sternpost of a steel or iron vessel, used as a support for the frames of the counter.

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