loophole

Meanings

1. A slit in a castle wall; today, any similar window for shooting a ranged weapon or letting in light.
2. A method of escape, especially an ambiguity or exception in a rule or law that can be exploited in order to avoid its effect.

1. To prepare a building for defense by preparing slits or holes through which to fire on attackers
2. To exploit (a law, etc.) by means of loopholes.

Etymology

From Middle English loupe (“opening in a wall”) + hole, from a Germanic source. By surface analysis, loop + hole. Compare Medieval Latin loupa, lobia and Middle Dutch lupen (“to watch”).