General:
* Drive: This is a very common synonym, particularly for campaigns with a specific goal, like a fundraising drive or a voter registration drive.
* Effort: This emphasizes the hard work and dedication involved in the campaign.
* Push: This suggests a concerted effort to achieve something.
Specific to certain types of campaigns:
* Crusade: This suggests a strong moral purpose, like a campaign against poverty or for social justice.
* Promotion: This is more appropriate for marketing campaigns.
* Operation: This is often used for military campaigns or complex, coordinated efforts.
Other options:
* Movement: This emphasizes a broader social or political change being sought.
* Drive: This suggests a focused effort to achieve a specific goal.
Ultimately, the best synonym for "campaign" will depend on the specific context of your sentence.