The word antonym is a noun, which is a person, place or thing.
The antonym for the word "antonym" is "synonym" (a word that means the same as another word). For example, the synonym of the word "dog" is "canine."
According to Dictionary.com, the word antonym came of use in the late 19th century. The word comes from the Greek word "anti" (opposite) and "nym" (name).
Knowledge of antonyms is very important in establishing mastery of the English language and is one of the basic language skills taught to school-age children, according to InstructorWeb.com.
Antonyms are also part of what are popularly referred to as the "-nym" family (acronym, antonym, synonym, homonym), words that can greatly boost your vocabulary.