1787 (intransitive), from Scottish, where apparently it survived as an alteration of glent, from Middle English glenten "gleam, flash, glisten" (mid-15c.), from a Scandinavian source (compare Norwegian gletta "to look," dialectal Swedish glinta "to shine"), from the group of Germanic *gl- words meaning "smooth; shining; joyous," from PIE root *ghel- (2) "to shine," with derivatives referring to bright materials and gold. Reintroduced into literary English by Burns. Related: Glinted; glinting.
"a gleam," 1826 (with a possible isolated use from 1540s in OED), from glint (v.).