la·ches /'la-chəz, 'lā-, -shəz/ n pl laches [Anglo-French lachesce laschesce negligence, from Old French lasche lax, ultimately from Latin laxare to loosen, from laxus slack]
1: undue delay in asserting a right or privilege compare statute of limitations
2 a: a doctrine permitting dismissal of a suit because a plaintiff's unreasonable delay in asserting a right or privilege has been detrimental to the defendant's ability to make a defense (as by resulting in the unavailability of witnesses or evidence)
a suit barred by laches
b: an affirmative defense based on this doctrine
Merriam-Webster’s Dictionary of Law. Merriam-Webster. 1996.