hard-rock

[hahrd-rok]

adjective

(loosely) of or relating to igneous or metamorphic rocks, as in mining (hard-rock mining) and geology (hard-rock geology).

Compare soft-rock geology.

Origin of hard-rock

First recorded in 1920–25

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018