Source : Webster's Revised Unabridged Dictionary (1913)

Insufficient \In`suf*fi"cient\, a. [L. insufficiens, -entis. See
   {In-} not, and {Sufficient}.]
   1. Not sufficient; not enough; inadequate to any need, use,
      or purpose; as, the provisions are insufficient in
      quantity, and defective in quality. ``Insufficient for His
      praise.'' --Cowper.

   2. Wanting in strength, power, ability, capacity, or skill;
      incompetent; incapable; unfit; as, a person insufficient
      to discharge the duties of an office.

   Syn: Inadequate; scanty; incommensurate; unequal; unfit;
        incompetent; incapable; inefficient.

Source : WordNet®

insufficient
     adj : of a quantity not able to fulfill a need or requirement;
           "insufficient funds" [syn: {deficient}] [ant: {sufficient}]