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.

The vitamin D deficient group also required more opioid medication.

From Science Daily • May 20, 2026

The county conducted an audit of Harm Reduction-SD in April 2023 that revealed “significant financial control weaknesses including insufficient bank reconciliations and a deficient general ledger,” prosecutors allege.

From Los Angeles Times • Feb. 19, 2026

"If it turns out the shipowners were deficient, they will expect the full force of the law," Lopez told reporters.

From Barron's • Jan. 27, 2026

“It is a very deficient law,” said Francisco Monaldi, a Venezuelan who directs the Latin America energy program at Rice University’s Baker Institute for Public Policy.

From The Wall Street Journal • Jan. 22, 2026

At last the relief authorities placed me in the South Side Boys’ Club and my wages were just enough to provide a deficient diet.

From "Black Boy" by Richard Wright

Vocabulary lists containing deficient

Tuesdays with Morrie

Looking to grow your vocabulary? Check out this interactive, curated word list from our team of English language specialists at Vocabulary.com – one of over 17,000 lists we've built to help learners worldwide!

Oh, No! Synonyms for "Bad"

Interested in learning more words like this one? Our team at Vocabulary.com has got you covered! You can review flashcards, quiz yourself, practice spelling, and more – and it's all completely free to use!

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

Want to remember this word for good? Start your learning journey today with our library of interactive, themed word lists built by the experts at Vocabulary.com – we'll help you make the most of your study time!