How to say "crusader" in Japanese

• クルセイダー
  nounA straight borrowing of the English word, keeping its sound and senses. It is not the ordinary way to say 'crusader', though; for a zealous campaigner, 運動家 is the word to use.
• 運動者うんどうしゃ
  nounSomeone taking part in a political movement; hence a crusader for a cause such as women's rights. This form is seldom the word you want — for this sense 運動家 is the word to use.
• 運動家うんどうか
  nounA person devoted to a movement or cause — an activist or campaigner. Choose this when 'crusader' means someone zealously fighting for social or political change, such as women's rights.

For the figurative 'crusader' — someone zealously devoted to a cause — 運動家 is the natural choice and 運動者 seldom the word you want; 「クルセイダー」 is the borrowed English word, kept for its foreign flavor.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

• クルセイダーcrusader
• 運動者うんどうしゃactivist (in a political movement)
• 運動家うんどうかactivist