"a gleam," 1826 (with a possible isolated use from 1540s in OED), from glint, v..

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 *ghel- (2) "to shine," with derivatives referring to bright materials and gold (see glass, n.). Reintroduced into literary English by Burns. Related: Glinted; glinting.