diehard
/ˈdaɪˌhɑrd/
noun
- A person who strongly supports something and refuses to change their beliefs or opinions, even when others do.
- My uncle is a diehard fan of the old baseball team and still wears their vintage cap.
- A few diehards stayed at the concert until the very last song in the rain.
- Even after the company changed its logo, the diehards refused to use the new design.
adjective
- Strongly loyal to a set of beliefs or habits and unwilling to change.
- She is a diehard supporter of traditional farming methods.
- His diehard commitment to the old software made it hard for the team to upgrade.
- The diehard fans camped outside the stadium for three days to get tickets.