thesaurus

The story

1. Ancient Greek · derived fromθησαυρός“storehouse, treasure”
2. Latin · borrowed fromthēsaurus
3. English todaythesaurus

16th century, borrowed from Latin thēsaurus, from Ancient Greek θησαυρός (thēsaurós, “storehouse, treasure”); its current English usage/meaning was established soon after the publication of Peter Roget's Thesaurus of English Words and Phrases in 1852. Doublet of treasure.

Words from the same roots