Толковый словарь английского языка Oxford English Reference - correlative

adj. & n. --adj. 1 (often foll. by with, to) having a mutual relation. 2 Gram. (of words) corresponding to each other and regularly used together (as neither and nor). --n. a correlative word or thing. Derivatives correlatively adv. correlativity n. Etymology: med.L correlativus (as COM-, RELATIVE)