Meaning of DIEHARD in English

DIEHARD

die ‧ hard /ˈdaɪhɑːd $ -hɑːrd/ BrE AmE noun [countable]

someone who opposes change and refuses to accept new ideas

—diehard adjective :

a few diehard fans

⇨ old habits die hard at ↑ die 1 (9)

Longman Dictionary of Contemporary English.      Longman - Словарь современного английского языка.