[ dih-fish-uh nt ]
/ dɪˈfɪʃ ənt /


lacking some element or characteristic; defective: deficient in taste.
insufficient; inadequate: deficient knowledge.


a person who is deficient, especially one who is mentally defective.

Nearby words

  1. deficiency,
  2. deficiency account,
  3. deficiency disease,
  4. deficiency judgment,
  5. deficiency symptom,
  6. deficient number,
  7. deficiently,
  8. deficit,
  9. deficit financing,
  10. deficit spending

Origin of deficient

1575–85; < Latin dēficient- (stem of dēficiēns, present participle of dēficere to fail, run short, lack, weaken), equivalent to dē- de- + fic-, combining form of facere to make, do1 + thematic -i- + -ent- -ent

Related forms Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for deficient

British Dictionary definitions for deficient


/ (dɪˈfɪʃənt) /


lacking some essential; incomplete; defective
inadequate in quantity or supply; insufficient
Derived Formsdeficiently, adverb

Word Origin for deficient

C16: from Latin dēficiēns lacking, from dēficere to fall short; see defect

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for deficient



1580s, from Latin deficientem (nominative deficiens), present participle of deficere "to desert, revolt, fail," from de- "down, away" (see de-) + facere "to do, perform" (see factitious).

Online Etymology Dictionary, © 2010 Douglas Harper

Medicine definitions for deficient


[ dĭ-fĭshənt ]


Lacking an essential quality or element.
Inadequate in amount or degree; insufficient.

The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.