crusade
n. countablen. a long and determined effort to change something you think is wrong. It can also refer to a series of religious wars in the past.
n. a vigorous campaign for political, social, or religious change; historically, any of the military expeditions undertaken by Christian powers in the 11th, 12th, and 13th centuries.
She led a crusade against plastic waste in her town.
The local newspaper started a crusade to improve safety standards at the city's public swimming pools.
What began as a personal crusade for better healthcare access eventually transformed into a nationwide movement that forced significant legislative reform in the capital.
From French croisade, introduced into English (in the French spelling) by 1575. The modern spelling emerges c. 1760,. Middle French croisade is introduced in the 15th century, based on Spanish cruzada (late 14th century) and Old Occitan crozada (early 13th century), both reflecting Medieval Latin cruciāta, cruxiata, the feminine singular of the adjective cruciātus used as an abstract noun. Adjectival cruciātus originally meant "tormented; crucified", but from the 12th century crucesignatus was also used for "marked with a cross; making the sign of the cross" and eventually "taking the cross" in the sense of "going on a crusade". Old Occitan crozada is used in the sense "[the Albigensian] crusade" in the Song of the Albigensian crusade, written c. 1213. From vernacular usage, Middle Latin cruciāta also comes to be used in the sense "crusade" from about 1270.
Often paired with the preposition 'against' to indicate the target of the campaign.