Source : Webster's Revised Unabridged Dictionary (1913)

Apportion \Ap*por"tion\, v. t. [imp. & p. p. {Apportioned}; p.
   pr. & vb. n. {Apportioning}.] [OF. apportionner, LL.
   apportionare, fr. L. ad + portio. See {Portion}.]
   To divide and assign in just proportion; to divide and
   distribute proportionally; to portion out; to allot; as, to
   apportion undivided rights; to apportion time among various
   employments.

Source : WordNet®

apportion
     v 1: distribute according to a plan or set apart for a special
          purpose; "I am allocating a loaf of bread to everyone on
          a daily basis"; "I'm allocating the rations for the
          camping trip" [syn: {allocate}]
     2: give out as one's portion or share [syn: {share}, {divvy up},
         {portion out}, {deal}]