Source : Webster's Revised Unabridged Dictionary (1913)

Incommensurate \In`com*men"su*rate\, a.
   1. Not commensurate; not admitting of a common measure;
      incommensurable.

   2. Not of equal of sufficient measure or extent; not
      adequate; as, our means are incommensurate to our wants.

   Syn: Inadequate; insufficient; disproportionate. --
        {In`com*men"su*rate*ly}, adv. --
        {In`com*men"su*rate*ness}, n.

Source : WordNet®

incommensurate
     adj : (often followed by `with') not corresponding in size or
           degree or extent; "a reward incommensurate with his
           effort" [ant: {commensurate}]