The Collaborative International Dictionary of English v.0.48:

Proportionate \Pro*por"tion*ate\, v. t. [imp. & p. p.
   Proportionated; p. pr. & vb. n. Proportionating.] [Cf.
   Proportion, v.]
   To make proportional; to adjust according to a settled rate,
   or to due comparative relation; to proportion; as, to
   proportionate punishment to crimes.
   [1913 Webster]