diehard
https://gyazo.com/abc11a45342d96d0292f442fe3398074
source: [男性がサイリウムを振り回しヲタ芸を披露しているGIF画像|無料GIF画像検索 GIFMAGAZINE 60281] noun often as modifier
頑固者, (頑固な)保守主義者; 〖形容詞的に〗頑固な, 保守主義の
e.g. she was a diehard Yankees fan
e.g. diehard traditionalists.
ORIGIN