subcontrary

[suhb-kon-trer-ee]

noun, plural sub·con·tra·ries. Logic.

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

Origin of subcontrary

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

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British Dictionary definitions for subcontrary

subcontrary

adjective

(of a pair of propositions) related such that they cannot both be false at once, although they may be true togetherCompare contrary (def. 5), contradictory (def. 3)

noun plural -ries

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

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