Laches (, , like "latches"; , ;
Law French: "remissness", "dilatoriness," from Old French
laschesse) refers to a lack of diligence and activity in making a legal claim, or moving forward with legal enforcement of a right, in particular with regard to
equity; hence, it is an
unreasonable delay that can be viewed as prejudicing the opposing [defending] party. When asserted in litigation, it is an
equity defense, that is, a defense to a claim for an equitable remedy. The person invoking laches is asserting that an opposing party has "slept on its rights," and that, as a result of this delay, circumstances have changed, witnesses and/or evidence may have been lost or no longer available, etc., such that it is no longer a just resolution to grant the
plaintiff's claim. Laches is associated with the maxim of equity, "Equity aids the vigilant, not the sleeping ones [that is, those who sleep on their rights]." Put another way, failure to assert one’s rights in a timely manner can result in a claim being barred by laches.