deficient

[dih-fish-uhnt] / dɪˈfɪʃ ənt /

ADJECTIVE

imperfect, inadequate

Synonyms

STRONGEST

defective faulty flawed impaired incomplete inferior insufficient lacking scarce skimpy unsatisfactory weak

WEAK

amiss bad damaged exiguous found wanting infrequent injured marred meager not cut out for not enough not make it not up to scratch outta gas rare scant scanty second fiddle second string short shy sketchy third-string unassembled unequal unfinished wanting

Antonyms

STRONGEST

abundant adequate enough perfect strong sufficient

WEAK

ample excessive faultless flawless satisfactory superfluous

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

Being truly deficient in B6 is rare, although sometimes levels can be a bit low, often alongside a lack of other B vitamins, such as B12, which can leave you feeling tired and nauseous.

From BBC • Apr. 22, 2026

The agreement Barnett reached with LaBeouf “contained a deficient and unlawful NDA that is unenforceable,” under California’s Stand Together Against Non-Disclosure Act, according to the complaint.

From Los Angeles Times • Mar. 26, 2026

Iran, which is an IMO member but does not sit on its council, hit out at the declaration, branding it "one-sided, unfair, inaccurate and legally deficient".

From Barron's • Mar. 19, 2026

“Our animals and us are actually super deficient in light, especially the most healing wavelengths that we have,” says Jackie Jolie, CEO of AnimaSol.

From The Wall Street Journal • Jan. 28, 2026

“You know he is as ungainly within as without. A deficient, ill-tempered, lowering, stupid fellow.”

From "Great Expectations" by Charles Dickens

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