Of words so related that one contrasts with the other "'rich' and 'hard-up' are contrastive terms" - incompatible
Strikingly different; tending to contrast "contrastive colours" - contrasting
Syntactically establishing a relation of contrast between sentences or elements of a sentence "disjunctive conjunctions like 'but', 'or', or 'though' serve a contrastive function"
See also: antonymous, contrast, different, disjunctive