Typically, a thesaurus will have both synonyms and antonyms that you can look for.
A dictionary or thesaurus
A thesaurus or a dictionary
a thesaurus
A Thesaurs
Use a thesaurus to find the words "normal" and "conventional."
Roget's Thesaurus Roget's Thesaurus
Depending on what you think the meaning of these words are. A synonym would be where two words mean the same thing, so clever and ignorant are antonyms. These words do have opposite meanings.
Thesaurus
almanac
A telephone book.
almanac
ENCYCLOPEDIA