Laches \Lach"es\, Lache \Lache\, n. [OF. lachesse, fr. lache lax, indolent, F. l[^a]che, ultimately fr. L. laxus loose, lax. See {Lax}.] (Law) Neglect; negligence; remissness; neglect to do a thing at the proper time; delay to assert a claim. It ill became him to take advantage of such a laches with the eagerness of a shrewd attorney. --Macaulay.