An open field; a large, open plain without considerable hills. SeeChampaign.
- A series of military operations undertaken to achieve a large-scale objective during a war: Grant's Vicksburg campaign secured the entire Mississippi for the Union.
- An operation or series of operations energetically pursued to accomplish a purpose: an advertising campaign for a new product; a candidate's political campaign.
- To engage in an operation planned to achieve a certain goal: campaigned through the jungles of Vietnam; campaigned for human rights.