Dictionary: a source of information about the words of a language, with information about their meaning, spelling, and pronunciation.
Thesaurus: a book that lists words with their synonyms or antonyms.
Synonyms: a word that has the same or nearly the same meaning as another word of the same language.“Big” and “large” are synonyms.
Antonyms: a word that has the opposite meaning of another word. “Late” is an antonym of “early.”