Learn how to say Crusades correctly in English with this tutorial pronunciation video.
Oxford dictionary definition of the word crusade:
(often capital) any of the military expeditions undertaken in the 11th, 12th, and 13th centuries by the Christian powers of Europe to recapture the Holy Land from the Muslims
(formerly) any holy war undertaken on behalf of a religious cause
a vigorous and dedicated action or movement in favour of a cause
to campaign vigorously for something
to go on a crusade
C16: from earlier croisade, from Old French crois cross, from Latin crux; influenced also by Spanish cruzada, from cruzar to take up the cross