This word is acceptable for play in the US & UK dictionaries that are being used in the following games:

• Lexulous
• Wordscraper
• Wordosaur

adj. Lacking an essential quality or element: deficient in common sense.

adj. Inadequate in amount or degree; insufficient: a deficient education.

adj. Lacking something essential; often construed with in.

adj. Insufficient or inadequate in amount.

adj. Wanting, to make up completeness; wanting, as regards a requirement; not sufficient; inadequate; defective; imperfect; incomplete; lacking

Lacking; wanting; incomplete.

Defective; imperfect; inadequate: as, deficient strength.

Not having a full or adequate supply: as, the country is deficient in the means of carrying on war.

adj. of a quantity not able to fulfill a need or requirement

adj. falling short of some prescribed norm

adj. inadequate in amount or degree

"Exactly how much vitamin D children and adults should get, and defining when they are deficient, is under debate."

lean    scant    short    skimpy    inadequate    poor    shy    depleted    low    light   

abundant    abounding    excessive    spare   

deficient number    deficient hyperbola   

deficit    deficiency    defector    defect    defective    defection   

inadequate    defective    imperfect    incomplete    lacking    poor    insufficient    short    scarce    scant   

Omniscient    beneficent    coefficient    efficient    inefficient    insufficient    omniscient    proficient    self-sufficient    sufficient   

defective    inadequate    inferior    unsatisfactory    unable    inaccurate    weak    absent    inappropriate    unfair