[an-til-uh-jiz-uh m]
noun Logic.
  1. a group of three inconsistent propositions, two of which are premises of a syllogism that contradict the third.

Origin of antilogism

1900–05; < Late Greek antilogismós, equivalent to anti- anti- + logismós calculation, derivative of logízesthai to calculate, derivative of lógos reckoning
Related formsan·til·o·gis·tic, adjectivean·til·o·gis·ti·cal·ly, adverb Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018