(crusades, crusading, crusaded)
1.
A crusade is a long and determined attempt to achieve something for a cause that you feel strongly about.
Footballers launched an unprecedented crusade against racism on the terraces...
= campaign
N-COUNT: oft N against/for n, N to-inf
2.
If you crusade for a particular cause, you make a long and determined effort to achieve something for it.
...a newspaper that has crusaded against the country's cocaine traffickers.
...an adopted boy whose cause is taken up by a crusading lawyer.
= campaign
VERB: V against/for n, V-ing
3.
The Crusades were the wars that were fought by Christians in Palestine against the Muslims during the eleventh, twelfth, and thirteenth centuries.
N-PROPER-PLURAL: the N