Meanings of words are found in the dictionary.
A thesaurus is a useful reference source for finding synonyms. It provides a list of words with similar meanings to the word you are looking up.
A thesaurus.
Thesaurus
Roget's Thesaurus Roget's Thesaurus
A thesaurus would be the ideal reference source to find synonyms for the word "angry."
You would use a thesaurus.
it means is mad or happy
An almanac
almanac
A thesaurus is a helpful reference source to find an antonym for "clever." Some antonyms for clever include obtuse, simple, or unintelligent.
A history textbook.
encyclopedia
in a almanac!
Wikipedia
encyclopedia