Yours, Etc.: Origins and Uses of 8 Sign-Offs
1888, from treasure trove (c.1550), from Anglo-French tresor trové (late 12c.), translating Latin thesaurus inventus, literally "treasure found." Originally any precious metal object one finds hidden whose owner is unknown. As this usually meant ancient hoards, the term came to mean "treasure hoard" in popular use. Rendered treasure found from mid-15c.