over the transom

Meaning

Prepositional phrase

• Unsolicited.
• Meeting a deadline by delivery after the day of the deadline but before opening of business the following business day.

Origin

• A transom is a lintel or crosspiece over a door; likely an alteration of Latin trānstrum. Refers to the idea of a writer tossing a manuscript through the open window over the door of the publisher's office. Alternatively, a "transom" is the nautical term for the back of a small boat. Something which "came in over the transom" would have suddenly (and presumably, surprisingly) entered through the "back door" of the craft, metaphorically.