What word best describes an "antonym"?

The term "antonym" specifically refers to a word that has an opposite meaning to another word. For instance, the antonym of "hot" is "cold," as these two words represent opposite ends of a temperature spectrum. Understanding antonyms is essential for developing vocabulary and improving language skills, as they help clarify meaning and enhance the ability to express contrasting ideas. The other options, while relevant to language, do not accurately define what an antonym is. For example, a word with a similar meaning is known as a synonym, which contrasts directly with the concept of antonyms.