hardrock DCHP-1 (pre-1967)
1a n. — Mining
mining in solid rock, especially quartz.
See also: quartz mining
1b n. — Mining
(attributive uses) pertaining to such rock or the mining of it.
2a n. — Slang
a strong, rough person of great endurance.
2b n. — Slang
(attributive uses) characterized by strong, rough, durable behavior.
3 n. — Slang
(attributive uses) unyielding; difficult to reason with; hard-headed.