Which of the following describes an "antonym"?

An antonym is defined as a word that has the opposite meaning of another word. For instance, the antonym of "hot" is "cold," as they represent opposing concepts. This definition highlights how antonyms serve to express contrasting ideas, which is crucial in enhancing understanding and vocabulary in language.

The other options do not align with this definition. A word with a similar meaning refers to synonyms, which are words that share the same or nearly the same meaning. A word that has multiple meanings describes polysemy, where one word can convey different meanings depending on context. Finally, a phrase that explains something does not pertain to the nature of antonyms but rather relates to definitions or descriptions. Understanding these distinctions helps clarify how antonyms function within the broader context of word relationships in language.