Webster's Revised Unabridged Dictionary · 1913

Crusade

Crusade (kr?-s?d") , noun

[French croisade, from Pr. crozada, or Sp cruzada, or Italian crociata, from a verb signifying to take the cross, mark one's self with a cross, from Latin crux cross; or possibly taken into English directly from Pr. Compare Croisade, Crosado, and see Cross.]

1.
Any one of the military expeditions undertaken by Christian powers, in the 11th, 12th, and 13th centuries, for the recovery of the Holy Land from the Muslims.
2.
Any enterprise undertaken with zeal and enthusiasm; as, a crusade against intemperance.
3.
A Portuguese coin. See Crusado.

Crusade , intransitive verb

To engage in a crusade; to attack in a zealous or hot-headed manner.
Cease crusading against sense. — M. Green