Of unknown origin; the original sense probably referred to gentle physical movements, which then shifted to aural noise. Has been derived from a Proto-Indo-European*leys-(“small, mild”), and compared with Ancient Greekλιαρός(liarós, “tepid, mild”), λοῖσθος(loîsthos, “the last”), and Lithuanianlíesas(“lean, skinny”),[1] though more recent scholarship does not seem to support these comparisons.
