What does transom mean?
Transom is a specialized noun with architectural and nautical uses. In a building, it usually means a horizontal member or glazed framework above a doorway, often called a transom window. On a ship, it refers to the transverse frame across the stern, a structure that closes the vessel’s rear and can contain windows, ports, and fittings. The word can also describe a horizontal beam spanning an opening or dividing an interior space. Because it is principally a technical term, transom generally appears in discussion of architecture, construction, boats, or ships rather than in casual conversation. Its defining idea is a piece laid transversely, or across, an opening or vessel. The term is useful for distinguishing the glazed or structural section above a door from the door itself, and the stern framework from a vessel’s keel or other longitudinal elements.
nounA transom is a horizontal structural member spanning an opening, especially the glazed section above a door; in nautical use, it is the transverse frame across a vessel’s stern.
- A horizontal member above a doorway or other opening, often forming a framework for panes of glass or another infill.
- The transverse frame or upper structure across the stern of a ship or other vessel.
- A horizontal structural beam spanning an opening or dividing an interior space.
"A wooden transom above the entrance contained several small panes of glass."
"The fanlight above the old church door is set in a wooden transom."
"The launch’s transom rose above the water as it accelerated."
The plural is used for separate transom windows, structural members, or ship stern frames.
"The old warehouse has two glazed transoms above its entrance."
A ship’s transom is its stern’s crossbar: the word evokes the timber laid across the back of a vessel.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does transom come from?
Transom comes from Medieval Latin transversum, meaning “cross-beam” or “transverse member.” That form derives from Latin transversus, “lying across,” ultimately from the prefix trans- and vertere, “to turn.” Its architectural and nautical uses reflect this basic sense of something positioned or extending across.
Related word forms
How transom is actually used
The word is chiefly architectural and nautical rather than everyday. In nautical usage, “over the transom” means astern, beyond the stern; “transom window” commonly refers to glazing above a door.
Easily confused with transom
A transom is a structural member or stern frame, while transverse is an adjective or noun describing something that crosses at right angles.