antitruth adjective 1noun 1forms 3 adjective1 •Opposed to truth. noun1 •That which is the opposite or negation of truth, especially of a mystical or religious truth.Vasu's archetypal self is the extroller of a negative truth, or antitruth; "the mythical structure" becomes its primary technique. — 2001 formsantitruths · more antitruth · most antitruth