A synonym is a word that has the same or nearly the same meaning as another word in the same language. Synonyms are used to improve word choice and to avoid overusing the same word. They can be found in every part of speech, including nouns, verbs, adjectives, adverbs, and prepositions. For example, "beautiful" and "attractive" are synonyms because they both refer to someone or something that is pleasing to the eye. Synonyms can be used to replace or clarify the meaning of a word. They are also necessary to avoid overusing the same word. Synonyms are different from antonyms, which are words that have opposite meanings.