I did a quick search but didn’t “find” much.
However, a “trove” (rhymes with “stove”) (a noun, short for “treasure trove”) is a discovery; a “find”; a valuable collection.
Under English common law, “trover” (as a noun) was a common law action to recover the value of goods wrongfully converted by another person to the wrongdoer’s own use.
The words “trove” and “trover” came to the English language from the Middle French verb “trover” (which means “to find”). The modern French verb is spelled “trouver” (roughly, pronounced “troo-vay”).
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J'ai trouvé cet argent-ci dans la rue" ("I found this money in the street"). That would be a treasure trove.
This isn’t a definition of treasure trove itself, but it's an old Revenue Ruling similar to the more authoritative Treasury regulation quoted above:
The finder of treasure-trove is in receipt of taxable income, for Federal income tax purposes, to the extent of its value in United States currency, for the taxable year in which it is reduced to undisputed possession.
--Rev. Rul. 61, 1953-1 C.B. 17.