crusader
//kruːˈseɪdər//
Noun
crusaderSingular
crusadersPlural
1
A person who participated in the medieval Christian military expeditions to recover the Holy Land from Muslims.
The crusaders traveled thousands of miles to reach the Holy Land.
2
A person who campaigns vigorously for political, social, or religious change; a zealous advocate for a cause.
She became a crusader for environmental protection.