subcontrary

[ suhb-kon-trer-ee ]

noun

, Logic.

, plural sub·con·tra·ries.

1. one of two propositions that can both be true but cannot both be false.

subcontrary

/ sʌbˈkɒntrərɪ /

adjective

1. See contradictory, contrary
   (of a pair of propositions) related such that they cannot both be false at once, although they may be true together Compare contrary contradictory

noun

1. a statement that cannot be false when a given statement is false

Word History and Origins

Origin of subcontrary¹

1595–1605; < Medieval Latin subcontrārius, Late Latin ( sub-, contrary ), originally as translation of Greek hypenantíos