Antonyms are two words that are opposed on a dimension of denotative meaning. Unlike the concept of synonymity, which dates back to Aristotle, the concept of antonymy is of recent origin -- the Webster's New Dictionary of Synonyms dates the first use of the term to 1867. Since the term was coined, people have accepted the concept and have felt quite capable of recognizing or generating antonyms. However, little thought has been given to opposites which resemble antonymy but are clearly not antonyms. These words, called pseudoantonyms, appear to be antonyms at first glance but closer inspection shows that they are not.
Herrmann, Douglas J. and Chaffin, Roger J. S.
"A Case of Mistaken Antonymy,"
Word Ways: Vol. 14
, Article 16.
Available at: http://digitalcommons.butler.edu/wordways/vol14/iss1/16