A projection (as a gun platform) from the side of a ship or tank. Also an air chamber along a watercraft to increase stability and auoyancy.
From the story “Actors” in the collection Dictation by Cynthia Ozick, page 54.
The usage in context here is pretty undistinguished, as the word appears in a list of words that the author of crossword puzzles happens to know. It’s not really worth quoting.