MEANING: noun: A zealous effort for an idea or cause.
verb intr.: To engage in a zealous effort.

ETYMOLOGY: A blend of Spanish cruzada + French croisade, both ultimately from Latin crux (cross). Earliest documented use: 1577.

CRUSAIDE - someone to assist you in making sure your wine is truly a product of Burgundy

CRUISADE - relentless campaign to go on a week-long all-inclusive vacation on a boat

TRUSADE - a real sadist