Based on the maxim that equity aids the vigilant and not those who procrastinate regarding their rights; Neglect to assert a right or claim that, together with lapse of time and other circumstances, prejudices an adverse party. Neglecting to do what should or could, have been done to assert a claim or right for an unreasonable and unjustified time causing disadvantage to another.
Laches is similar to 'statute of limitations' except is equitable rather than statutory and is a common affirmative defense raised in civil actions.
Laches is derived from the French 'lecher' and is nearly synonymous with negligence.
In general, when a party has been guilty of laches in enforcing his right by great delay and lapse of time, this circumstance will at common law prejudice and sometimes operate in bar of a remedy which is discretionary for the court to afford. In courts of equity delay will also generally be prejudicial.
But laches may be excused from ignorance of the party's rights; from the obscurity of the transaction; by the pendency of a suit, and; where the party labors under a legal disability, as insanity, infancy and the like.