Answer: goldmine

AnswerCrossword Clue
GOLDMINEProfitable venture
GOLDMINELucrative venture
GOLDMINEProspector's quest
GOLDMINESource of great wealth
GOLDMINEBonanza
GOLDMINESource of sudden wealth
GOLDMINESource of great profit
GOLDMINESource of wealth