Emily Dickinson Lexicon

CAM-PAIGN', or CAM-PAIN', n. [campa'ne; Fr. campagne; It. campagna; Sp. compaña; Port. companha, from camp. This should be written campain, as Mitford writes it.]

1. An open field; a large open plain; an extensive tract of ground without considerable hills. [See Champaign.]
2. The time that an army keeps the field, either in action, marches, or in camp, without entering into winter quarters. A campaign is usually from spring to autumn or winter; but in some instances, armies make a winter campaign.