Meaning

noun restraint consisting of a rope (or light chain) used to restrain an animal

noun the cardinal number that is the sum of one and one and one

noun a figurative restraint

originFrom Middle English leesshe, leysche, lesshe, a variant of more original lease, from Middle English lees, leese, leece, lese, from Old French lesse (modern French laisse), either from Latin laxa, feminine form of laxus (“loose”) or, more probably, from a deverbal of Old French lesser, laissier, from Latin laxāre (“loose”); compare lax. Doublet of laisse.

Etymology from Wiktionary, CC BY-SA 3.0