Laches (equity)

Laches is an equitable defense, or doctrine, in an action at law. The person invoking laches is asserting that an opposing party has "slept on its rights", and that, as a result of this delay, that other party is no longer entitled to its original claim. Put another way, failure to assert one’s rights in a timely manner can result in claims being barred by laches. Laches is a form of estoppel for delay. In Latin,Vigilantibus non dormientibus æquitas subvenit.Equity aids the vigilant, not the negligent (that is, those who sleep on their rights).
See more at Wikipedia.org...