peep sight(n = noun.artifact) - rear gunsight having an adjustable eyepiece with a small aperture through which the front sight and the target are aligned;
is a kind of gun-sight, gunsight
An adjustable piece, pierced with a small hole to peep through in aiming, attached to a rifle or other firearm near the breech; -- distinguished from an
at first sight, battle sight, breech sight, in plain sight, in sight, keep in sight, line of sight, lose sight of, not by a blame sight, not by a long sight, open sight, out of sight, panoramic sight, peep, second sight, sight, sight bill, sight draft, sight gag, sight see, telescope sight, telescopic sight