The story
Etymology from Wiktionary, CC BY-SA 4.0.
Today it means: A word that is nearly an antonym, when an antonym is defined strictly by complete negation or polar oppositeness. (Many reference works use a looser definition of antonym that lumps these words into the single category of antonyms; some make the more rigorous distinction.) Full definition →
Etymology from Wiktionary, CC BY-SA 4.0.