1. The hole by which the key is inserted into a lock.
In an ordinary house- or room-door the keyhole usually goes right through, and thus affords opportunities of peeping, listening, etc., which are often alluded to: see the quots.
c. 1592. Marlowe, Jew of Malta, II. Wks. (Rtldg.), 158/2. Yet through the key-hole will he talk to her.
1592. Nashe, P. Penilesse (1843), 57. If I would raunge abroad, and looke in at Sluggards’ key-holes.
1635. ? Herrick, Fairy Queen, ii. in Hesper. (1869), App. 478. When mortals are at rest … Through key-holes we do glide.
a. 1715. Burnet, Own Time (1766), II. 212. He looked through the key-hole and there saw him lying dead.
1833. N. Arnott, Physics (ed. 5), II. 222. A candle carried past a key-hole, throws its light on the opposite wall.
1887. Ruskin, Præterita, II. ii. 52. An ominously Æolian keyhole in a vile inn.
2. A hole made to receive a peg or key used in carpentry or engineering.
1703. T. N., City & C. Purchaser, 33. Round-bolts … with a Head at one end, and a Key-hole at the other.
c. 1860. H. Stuart, Seaman’s Catech., 61. The lower keyholes should be clear, to allow the water to run out freely.
3. In New Brunswick: A round harbor or cove with narrow entrance.
1896. W. F. Ganong, in Trans. R. Soc. Canada, Ser. II. II. ii. 210.
4. attrib., as key-hole prospect, slit, view; keyhole escutcheon, an escutcheon-shaped plate of metal surrounding a keyhole; keyhole guard, -protector, a metal plate that falls over (or into) and closes a keyhole; keyhole limpet, a gastropod of the family Fissurellidæ, having a shell with an aperture at the apex; keyhole saw, a narrow saw for cutting keyholes, etc.; keyhole whistler, slang. (see quot.)
1889. Sci. Amer., LXI. 195. Bennett’s improved *key-hole guard … preventing any view through the keyhole.
1869. J. G. Wood, Common Shells, 96. In the Tusk-shells there is an aperture at the peak, and the same is the case with the *Key-hole Limpet Fissurella reticulata.
1885. Stand. Nat. Hist., I. 320. The Fissurellidæ, or key-hole limpets, are structurally closely allied to the … Haliotidæ.
1851. H. Melville, Moby-Dick, xvii. 92. The *key-hole prospect was but a crooked and sinister one.
1812–6. J. Smith, Panorama Sci. & Art, I. 107. A small kind of compass-saw, called a *key-hole saw, is used for quick curves, such as key-holes.
1881. Gentl. Mag., Jan., 65. A man standing on his head to keep him quiet, and another cutting a *‘keyhole’ slit in his ear.
1851. Mayhew, Lond. Labour, I. 311/1. *‘Keyhole whistlers,’ the skipper-birds are sometimes called…. They start early to good houses for victuals, when gentlefolk are not up.
Hence Keyhole v., trans. (of a bullet in target-practice) to strike the target in such a way as to make a hole of the form of a key-hole.
1890. Cent. Dict. cites Reynolds.
