[noun] [C] [disapproving] - someone who is unwilling to change or give up their ideas or ways of behaving, even when there are good reasons for them to do soOnly a few diehards on the right of the party object to the proposed changes.He's a diehard conservative/reformer/cynic.See also die hard at die (STOP LIVING).
DIEHARD
Meaning of DIEHARD in English
Cambridge English vocab. Кембриджский английский словарь. 2012