RhymeZone: headrail definitions

Definitions of headrail:

noun: The supporting rail of a blind (such as a Venetian blind) that encloses its mechanism; a headbox.
noun: (nautical) A railing, on a sailing ship, behind the figurehead.
noun: (nautical, slang, obsolete, in the plural) A person's teeth.

(Definitions from Wiktionary)