citigrade,a.|ˈsɪtɪgreɪd| [f.mod.L. citigrada, f. L. citus swift + gradus step: cf. F. citigrade.] lit. Moving swiftly; applied to a tribe of swift-moving spiders, Citigrada, and subst. one of these. 1845Darwin Voy.Nat. viii. (1870) 160 A spider..which in its general appearance resembled a Citigrade.