| Keyhole 1. (n.) A hole or aperture in a door or lock, for receiving a key. 2. (n.) A hole or excavation in beams intended to be joined together, to receive the key which fastens them. 3. (n.) a mortise for a key or cotter. Thesaurus Entries air hole, armhole, blowhole, bullet-hole, bunghole, cringle, deadeye, eye, eyelet, gasket, grommet, guide, knothole, loop, loophole, manhole, mousehole, peephole, pigeonhole, pinhole, placket, placket hole, porthole, punch-hole, spiracle, tap, vent, venthole |