dead + light
deadlight (plural deadlights)
- (nautical) A strong (often wooden) shutter fitted over a porthole, that can be closed in bad weather to keep water out and discourage the glass windows from breaking.
- (nautical) A deck prism, a device to allow light into the cabin of boat through the deck.
- (figuratively) An eyelid.
1913, Joseph C. Lincoln, chapter 6, in Mr. Pratt's Patients:
- He had one hand on the bounce bottle—and he'd never let go of that since he got back to the table—but he had a handkerchief in the other and was swabbing his deadlights with it.