in zoology, "having pincer-like claws," 1826 as a term in zoology; 1920 in chemistry, from Modern Latin chela "claw" of a crab or lobster (from Greek khēlē "claw, talon, pincers, cloven hoof," a word of uncertain origin) + -ate (2). In chemistry from 1920. Related: Chelated; chelating; chelation.