1738, so called because discovered by English anatomist William Cowper (1666-1709); for the surname see Cooper.
1690s, from French glande (Old French glandre "a gland," 13c.), from Latin glandula "gland of the throat, tonsil," diminutive of glans (genitive glandis) "acorn, nut; acorn-shaped ball," from PIE root *gwele- (2) "acorn" (source also of Greek balanos, Armenian kalin, Old Church Slavonic zelodi "acorn;" Lithuanian gilė "acorn"). Earlier English form was glandula (c. 1400); Middle English also had glandele "inflamed gland" (c. 1400). Extended from tonsils to glands generally.