false·ness noun (-es) Etymology: Middle English falsnesse, from fals false + -nesse -ness : the quality or state of being false: as a.: contrariety to the fact : inaccuracy < the falseness of a wicked rumor > b. (1): unfaithfulness, treachery, perfidy < unbraided him for his falseness to his wife > (2): lack of integrity or uprightness : insincerity < there is a certain falseness about the man that I dislike >