From Proto-Baltic *glitus, *glītus, from Proto-Indo-European *glīt-, the zero grade of *gley- (“to stick; to spread, to smear”) with an extra -t. From a parallel Baltic yo-stem from *glītyas came Latvian dialectal glīšs. The meaning changed from “slippery” to “smooth; tight-fitting” (a meaning still attested in folk songs), to “pleasant, pretty.” Cognates include Lithuanian glitùs, dialectal glytùs (“slimy, sticky; slick, slippery”), Ancient Greek γλοιός (gloiós, “sticky, slippery”), Late Latin glus (“glue”), accusative glutem (whence English glue), from earlier Latin glūten.