crusade >> /kruˈseɪd/
Definition: [noun] Each of a series of medieval military expeditions made by Europeans to recover the Holy Land from the Muslims in the 11th, 12th, and 13th centuries.A war instigated for alleged religious ends.
Example: the fanaticism engendered by the Crusades
Definition: [noun] A vigorous campaign for political, social, or religious change.
Definition: [intransitive verb] Lead or take part in a vigorous campaign for social, political, or religious change.
Example: he crusaded against gambling in the 1950s