Main Entry: the·sau·rus

Pronunciation: \thi-ˈsȯr-əs\

Function: noun

Inflected Form(s): plural the·sau·ri \-ˈsȯr-ˌī, -ˌē\ or the·sau·rus·es \-ˈsȯr-ə-səz\

Etymology: New Latin, from Latin, treasure, collection, from Greek thēsauros

Date: circa 1823

1 : treasury, storehouse
2 a : a book of words or of information about a particular field or set of concepts; especially : a book of words and their synonyms b : a list of subject headings or descriptors usually with a cross-reference system for use in the organization of a collection of documents for reference and retrieval

— the·sau·ral \-ˈsȯr-əl\ adjective