The term 'Fixed Portion' can be broken down into two words, 'RATION' and 'UNIT'. RATION is a noun meaning a fixed portion or allowance of food, fuel, or other commodities distributed or allotted usually by official decree. A UNIT is a single thing, person, or group, especially when thought of as part of a larger whole. Together, the two words form the phrase 'Fixed Portion', which refers to a specific amount of something that is allocated or distributed in a consistent manner.