an ambiguity (especially one in the text of a law or contract) that makes it possible to evade a difficulty or obligation
a small hole in a fortified wall; for observation or discharging weapons
A slit in a castle wall; today, any similar window for shooting a ranged weapon or letting in light.
To prepare a building for defense by preparing slits or holes through which to fire on attackers
The word "loophole" comes from Middle English, combining "loupe," meaning an opening in a wall, with "hole." Although it is often mistakenly seen as a blend of "loop" and "hole," its true origin lies in the Germanic root for a gap or aperture.