D defs.my
Entry 2 senses Webster, 1913

Pay dirt

· IPA
01 Earth, rock, etc., which yields a profit to the miner.
  1. 1.
    Earth, rock, etc., which yields a profit to the miner.(Mining) [Western U. S.]
  2. 2.
    a discovery, especially after an exploratory process, which yields a profit or sought-after benefit; -- used especially in the phrase “to hit pay dirt”.