The term "treasure-trove" is a legal compound with a rich Anglo-Norman heritage. Its first element, "treasure", descends from Latin 'thesaurus', originally meaning a storehouse for valuables. The second element, "trove", originates from the Old French verb 'trover', meaning "to find", which itself has debated Germanic roots. Literally, the phrase meant "found treasure". In medieval English common law, it specifically denoted precious metals found hidden with no evidence of the original owner, granting possession to the Crown or the finder. Over time, its meaning broadened beyond strict legal contexts to describe any valuable collection or discovery, preserving the core idea of a fortunate and valuable find.

Structure: treasure + trove treasure: From Old French 'tresor', from Latin 'thesaurus', meaning "hoard, treasury". Functions as the core noun denoting something of great value. trove: From Anglo-French 'trove', past participle of 'trover' (to find), from Old French 'trover', of Germanic origin. Functions as a noun meaning "a find" or "something discovered".