Definitions

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.

Vomiting was only reported in the deficient group, although researchers said the difference was too small to be considered statistically significant.

From Science Daily • May 20, 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

Deere leverages AI to help farmers cut costs—by reducing labor required to operate equipment, minimizing wasted crop chemicals, and applying fertilizer more precisely where soil nutrients are deficient.

From Barron's • Feb. 2, 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

Cal Tech was not the place—Linus was too great a man to waste his time teaching a mathematically deficient biologist.

From "Double Helix" by James D. Watson

Vocabulary lists containing deficient

Tuesdays with Morrie

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50 Words from Jane Austen's "Pride & Prejudice"

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