deficiency

American  

[dih-fish-uhn-see] / dɪˈfɪʃ ən si /

Obsolete, deficience

noun

deficiencies plural

1. the state of being deficient; lack; incompleteness; insufficiency.

   Synonyms:

   scarcity, paucity, inadequacy, shortage

2. the amount lacked; a deficit.

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deficiency British  

/ dɪˈfɪʃənsɪ /

noun

1. the state or quality of being deficient

2. a lack or insufficiency; shortage

3. another word for deficit

4. biology the absence of a gene or a region of a chromosome normally present

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Other Word Forms

Derived Forms

• nondeficiency
  noun
• predeficiency
  noun

Inflected Forms

Nouns

• deficiencies
  plural

Etymology

Origin of deficiency

First recorded in 1625–35; from Late Latin dēficientia, Latin dēficient- (stem of dēficiēns ); see origin at deficient, -ency

Explanation

A deficiency is an insufficient amount of something. If you feel sluggish and tired all day, you might have an iron deficiency, meaning you aren't eating enough iron-rich foods. You are most likely to hear the word deficiency in regard to health, like a sleep deficiency. But you can use deficiency to describe other kinds of lack — a deficiency of fun that occurred while your friends were out of town. Deficiency also means a failure or shortcoming, like a deficiency in math class, which might result in a notice from school — known as a deficiency — being mailed to your home.

Example Sentences

See Examples For:

deficiency deficiencies

US Defence Secretary Pete Hegseth has announced that all military personnel aged 30 and over will be screened for testosterone deficiency as part of their annual health checks.

From BBC ● Jul. 17, 2026

The Pentagon plans to screen soldiers for testosterone deficiency as Defense Secretary Pete Hegseth continues his revamp of the country’s military.

From The Wall Street Journal ● Jul. 15, 2026

These factors include age, sex, ethnicity, body mass index, smoking status, existing medical conditions, previous muscle problems, vitamin D deficiency, medication use, and whether a person has been prescribed statins.

From Science Daily ● Jun. 30, 2026

Rajan takes vitamin D, a prebiotic, protein, fibre and creatine - in what he describes as a "supplement stack" - to target areas where he could have a deficiency.

From BBC ● Jun. 20, 2026

Her own father’s perfect exemption from any thought of the kind, the entire deficiency in him of all such sort of penetration or suspicion, was a most comfortable circumstance.

From "Emma" by Jane Austen

The report expressed concern about audit findings that identified “significant deficiencies in internal control ... that leave the district’s assets susceptible to misstatement, theft, or fraud.”

From Los Angeles Times ● Jul. 9, 2026

"The investigation, prosecution, and trial of Bilal Mohammed and Yusufu Mieraili have been rife with human rights violations and have exposed some of the systemic deficiencies of Thailand's criminal justice system."

From BBC ● Jun. 11, 2026

But targeted use of vitamin D, vitamin B12, folate and, in some cases, a multivitamin or protein supplement can help when deficiencies or low intake are present.

From Science Daily ● Jun. 6, 2026

Eroding admissions standards and obscuring academic deficiencies set students up for failure.

From The Wall Street Journal ● May 28, 2026

Therefore, enviously, gloatingly, he exacts vengeance upon us for the unalterable deficiencies in his own life.

From "Newjack: Guarding Sing Sing" by Ted Conover

Related Words

• dearth
• defect
• failing
• failure
• fault
• flaw
• frailty
• glitch
• insufficiency
• lack
• scarcity
• shortage
• shortcoming
• weakness