An antonym is a word that means the opposite of another word. Antonyms are usually listed at the end of definitions in the dictionary, or at the end of a list of synonyms in the thesaurus. Sometimes a thesaurus will list antonyms under the heading “Opposites,” but it is showing terms that are antonyms.
Knowing antonyms can help you build a web of associations between words (and their opposites). Sometimes the antonym of an unfamiliar word turns out to be a word you know really well, so knowing the antonym might help you to better understand or remember the unfamiliar word. Antonyms help show the contrasting relationships between words as well.
Let’s look a couple of examples!
Example #1: belie (verb): to give a false impression of something/someone; to contradict, or disguise
Example #2: groundbreaking (adjective): innovative, pioneering, radical, trailblazing