WordNet
n. rations issued for United States troops in the field
Wikipedia
A field ration, or combat ration, is a canned or pre-packaged meal, easily prepared and eaten, transported by military troops on the battlefield. They are distinguished from regular military rations by virtue of being designed for minimal preparation in the field, using canned, pre-cooked or freeze-dried foods, powdered beverage mixes and concentrated food bars, as well as for long shelf life.
Such meals also prove invaluable for disaster relief operations, where large stocks of these can be ferried and distributed easily, and provide basic nutritional support to victims before kitchens can be set up to produce fresh food.
Most armies in the world today now field some form of pre-packaged combat ration, suitably tailored to meet national or ethnic tastes.