We have put together a list of words that are similar to DEFICIENT.

17 Alternative Words Similar to deficient

1 Insufficient Adjective      Synonym Words Like Insufficient
2 Inferior Adjective      Synonym Words Like Inferior
3 Lacking Adjective      Synonym Words Like Lacking
4 Wanting Adjective      Synonym Words Like Wanting
5 Sufficient Adjective      Antonym Words Like Sufficient
6 Meager Adjective      Related Words Like Meager
7 Meagerly Adjective      Related Words Like Meagerly
8 Meagre Adjective      Related Words Like Meagre
9 Scrimpy Adjective      Related Words Like Scrimpy
10 Stingy Adjective      Related Words Like Stingy
11 Depleted Adjective      Similar Words Like Depleted
12 Lean Adjective      Similar Words Like Lean
13 Light Adjective      Similar Words Like Light
14 Low Adjective      Similar Words Like Low
15 Poor Adjective      Similar Words Like Poor
16 Scant Adjective      Similar Words Like Scant
17 Short Adjective      Similar Words Like Short

4 examples of deficient

1 deficient parts; deficient estate; deficient strength; deficient in judgment.
2 lacking in stamina
3 tested and found wanting
4 deficient in common sense

10 definitions of deficient

1 Wanting, to make up completeness; wanting, as regards a requirement; not sufficient; inadequate; defective; imperfect; incomplete; lacking
2 of a quantity not able to fulfill a need or requirement
3 falling short of some prescribed norm
4 inadequate in amount or degree
5 Lacking an essential quality or element: deficient in common sense.
6 Inadequate in amount or degree; insufficient: a deficient education.
7 Lacking; wanting; incomplete.
8 Defective; imperfect; inadequate: as, deficient strength.
9 Not having a full or adequate supply: as, the country is deficient in the means of carrying on war.
10 Lacking something essential; often construed with in.
We get our data from many different dictionaries across the web:
Wordnik, Wiktionary, Century, American Heritage, Gcide