the world > space > relative position > condition of being open or not closed > an opening or aperture > [noun] > keyhole (3)
A hole in a lock into which the key is inserted.
(a) a keyhole; (b) a hole into which a lock (sense 5) is fitted; †spec. (Firearms) a recess in which the lock sits (obsolete).
(a) a slot cut into the surface of a shaft, workpiece, etc., into which a key (sense A. 12a) fits; (b) a shaped hole in a lock through which a key…