Hardcore means extreme and uncompromising in style or belief. Hardcore fans, a hardcore approach, hardcore punk.
It names musical genres — hardcore punk and hardcore techno both mean the fast uncompromising end of a style — and a hardcore of supporters means the group who never leave. In building, hardcore is the broken stone laid under a foundation.
1adjectivehardcoreExtreme and uncompromising in style or belief.
“He's a hardcore vegan who won't even wear leather shoes.”
hardcore is a quality of extremity.
Hard plus core, from the phrase hard to the core. The building sense is recorded first, in 1936.
From hard + core: hard to the core; 1936 (n.); 1951 (adj.)
Etymology from Wiktionary, CC BY-SA