field gun

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun An artillery piece, originally a smaller gun that could accompany a field army on the march and when in combat could be moved about the battlefield in response to changing circumstances.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun movable artillery (other than antiaircraft) used by armies in the field (especially for direct support of front-line troops)