The term 'Army in the Field' is a phrase used to describe a military force that is actively engaged in combat operations. The crossword solution for this term is ANTS, which stands for 'Active Non-Traditional Soldiers'. This term is used to refer to soldiers who are not part of the traditional military structure, such as those who are part of a militia or volunteer forces. These soldiers often play an important role in providing support and assistance to the regular army in the field.