Apportion, portion, parcel, ration and prorate all mean to divide something carefully and distribute it among a number.
Apportion suggests division on a just, fair, or equitable basis; it does not, however, imply equality in the divisions or in the persons or things affected by the distribution.
- apportioned his time among various employments
- apportion the residue of an estate according to the terms of a will
- to apportion the judicial power between the supreme and inferior courts
—John Marshall
Portion (often with out) commonly suggests division into more or less equal shares.
- in the portioning out of war resources China had been left at the end of the table
—Feis - the country was portioned out among the petty chiefs
Parcel (usually with out) does not always imply immediate distribution, but it does imply division for the sake of ultimate distribution (as among purchasers or heirs); it is the preferred word when what is divided is cut into pieces, separated into lots, or distributed in small amounts.
- it could be parceled out into lots fifty by one hundred feet at five hundred dollars per lot
—Dreiser - colonies were estates to be exploited for the benefit of the home merchants, and the world was parceled out among privileged companies
—Randall
Ration usually implies authoritative allowance and an equal division of necessities (as fuel, food, or clothing) according to some principle (as of adequacy, sufficiency, or dietary variety or, when the available supply is limited or scanty, of fairness to all).
- ration the food for the horses
- where capital is short, it must be rationed intelligently, in the same way as gasoline and sugar were rationed in wartime
—Lans - the drinking water was rationed during the prolonged voyage
Prorate implies proportional division (sometimes proportional assessment) for the sake of fairness to those concerned: it may imply an authoritative decision as by a legislature, or an agreement among those concerned.
- prorate employment among the workers during slack seasons
- prorate overhead expenses among the various departments of a company
- the entire field was to be put in truck crops, and the yield prorated to the workers
—Lord