adjective C2 Proficient Uncommon

deficient

dih-FIH-shuhnt

Deficient (adjective) means lacking something necessary or sufficient; inadequate. Example: “His diet was deficient in essential vitamins.”

adjective

Lacking something necessary or sufficient; inadequate.

"His diet was deficient in essential vitamins."

"The bridge was found structurally deficient after the inspection."

How to use deficient

Learner’s notes

Common pairings

deficient in nutritionally deficient

more deficient comparative, deficients plural, most deficient superlative

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Can you complete this real example?

His diet was _____ in essential vitamins.

From Latin dēficiēns, the present participle of dēficere ("to lack, fail"), the same root as "defect."

Origin: Latin

insufficient

sufficient wanting excessive lacking inadequate insufficient satisfactory abundant

client orient ancient patient salient ambient lenient quotient obedient nutrient gradient sentient

What does “deficient” mean?

The word “deficient” means lacking something necessary or sufficient; inadequate.

How do you pronounce “deficient”?

“Deficient” is pronounced dih-FIH-shuhnt (/dɪˈfɪʃənt/ in IPA).

How do you use “deficient” in a sentence?

Here is “deficient” used in a sentence: “His diet was deficient in essential vitamins.”

What part of speech is “deficient”?

“Deficient” is an adjective.

Where does the word “deficient” come from?

The word “deficient” comes from Latin. From Latin dēficiēns, the present participle of dēficere ("to lack, fail"), the same root as "defect.".

Is “deficient” a common word?

“Deficient” is an uncommon word in modern English, usually learned at around the C2 level.

sufficient wanting excessive lacking inadequate insufficient satisfactory abundant