The Collaborative International Dictionary of English v.0.48:

Deficient \De*fi"cient\, a. [L. deficiens, -entis, p. pr. of
   deficere to be wanting. See Defect.]
   Wanting, to make up completeness; wanting, as regards a
   requirement; not sufficient; inadequate; defective;
   imperfect; incomplete; lacking; as, deficient parts;
   deficient estate; deficient strength; deficient in judgment.
   [1913 Webster]

         The style was indeed deficient in ease and variety.
                                                  --Macaulay.
   [1913 Webster]

   Deficient number. (Arith.) See under Abundant. --
      De*fi"cient-ly, adv.
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