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die–hard

die–hard /ˈdaɪˌhɑɚd/ adjective
die–hard
/ˈdaɪˌhɑɚd/
adjective
Britannica Dictionary definition of DIE–HARD
[more die–hard; most die–hard]
especially : very loyal to a set of beliefs and not willing to change those beliefs see also die hard at 1die

— diehard

noun, plural diehards [count]