D defs.my
Entry 2 senses Webster, 1913

Contraposition

· Con·tra·po·si·tion · IPA /ˈkɒntɹəpəˈzɪʃən/
01 n. A placing over against; opposite position.
  1. 1.
    A placing over against; opposite position.[Obs.]
  2. 2.
    A so-called immediate inference which consists in denying the original subject of the contradictory predicate; e. g.: Every S is P; therefore, no Not-P is S.(Logic)