Keyhole

1. n. a mortise for a key or cotter.
2. n. A hole or apertupe in a door or lock, for receiving a key.
3. n. A hole or excavation in beams intended to be joined together, to receive the key which fastens them.

The word meanings were obtained from OPTED(The Online Plain Text English Dictionary), which is based on “The Project Gutenberg Etext of Webster’s Unabridged Dictionary” which is in turn based on the 1913 US Webster’s Unabridged Dictionary (See Project Gutenburg), as a text file.