early 14c., glotien "to feed to repletion" (transitive), probably from Old French glotir "to swallow, gulp down, engulf," from Latin glutire/gluttire "to swallow, gulp down" (see gullet). Intransitive sense "feed (oneself) to repletion" is from c. 1400. Related: Glutted; glutting.
1530s, "a gulp, a swallowing," from glut (v.). Meaning "condition of being full or sated" is 1570s; mercantile sense "superabundance, oversupply of a commodity on the market" first recorded 1590s.