- hard-core, hardcore - stubbornly resistant to change or improvement; "hard-core addicts"
Antonym: flexible (indirect, via inflexible)
- hard-core, hardcore - intensely loyal; "his hard-core supporters"
Antonym: disloyal (indirect, via loyal)
- hard-core, hardcore - extremely explicit; "hard-core pornography"
Antonyms: implicit, inexplicit (indirect, via explicit)