|kän.trə+ noun
Etymology: Late Latin contraposition-, contrapositio, from Latin contrapositus (past participle of contraponere to place opposite, from contra- + ponere to put, place) + -ion-, -io -ion — more at position
1. : a placing over against : opposition , antithesis
2. logic : an operation of immediate inference in which the terms of a given proposition are permutated and negated (as given the contraponend “all S is P”, there follows the contrapositive “all not-P is not-S” and vice versa)