Transom (noun)

1. A horizontal crosspiece separating a door from a window or fanlight above it.
2. A transverse structural member in the stern of a ship that extends across the stern and strengthens the rudder post.

Origin:

Late middle english: from old french transome, from late latin trānsōma, from latin trāns- 'across' + ōma 'eye', on the pattern of transept.

Examples:

1. The transom above the door was opened to let in the cool breeze.
2. The ship's transom was damaged in the storm, causing the rudder to break.
3. The transom window provided a source of natural light in the room.
4. The transom in the bathroom allowed fresh air to circulate.
5. The transom provided a visual break in the facade of the building.