Synonym
Part of speech: noun
Definition: A word or phrase with a meaning that is the same as, or very similar to, another word or phrase. Any of the formal names for the taxon, including the valid name (i.e. the senior synonym). Any name for the taxon, usually a validly published, formally accepted one, but often also an unpublished name.
Thesaurus
Part of speech: noun
Definition: A publication, usually in the form of a book, that provides synonyms (and sometimes antonyms) for the words of a given language.A dictionary or encyclopedia.A hierarchy of subject headings—canonic titles of themes and topics, the titles serving as search keys.