trove : Idioms & Phrases

• noun treasure of unknown ownership found hidden (usually in the earth)
  trove.
  
• noun any collection of valuables that is discovered
  
  • her book was a treasure trove of new ideas
  • mother's attic was a treasure trove when we were looking for antiques

WordNet

Treas"ure-trove` noun

Etymology

Treasure + OF. trové, F. trouvé, p. p. of OF. trover to find, F. trouver. See Trover.

Definitions

1. (Common Law) Any money, bullion, or the like, found in the earth, or otherwise hidden, the owner of which is not known. In England such treasure belongs to the crown; whereas similar treasure found in the sea, or upon the surface of the land, belongs to the finder if no owner appears.

Webster 1913