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

And testosterone deficiency is hard to test for, because it varies so much during the diurnal cycle.

From The Wall Street Journal ● Jul. 24, 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

Many people in England who are considered at higher risk for vitamin D deficiency may not be getting enough of the nutrient at any time of year, according to new research.

From Science Daily ● Jun. 24, 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

Cruelly, callously, admissions committees agreed to overlook serious academic deficiency.

From "Hunger of Memory" by Richard Rodriguez

The BBC has found increasing numbers of people are arriving at hospitals across the South East either malnourished or with nutrient deficiencies.

From BBC ● Jul. 21, 2026

Officiating deficiencies have led to canceled games and shortened seasons.

From The Wall Street Journal ● Jul. 14, 2026

Recent amendments to be considered include assessing a kindergartner’s math knowledge rather than screening for math deficiencies, something that would help identify students who need additional support.

From Los Angeles Times ● Jun. 30, 2026

Vecenie pointed out that López doesn’t shoot well and has defensive deficiencies, saying that his game might be better suited for European leagues than the NBA.

From Los Angeles Times ● Jun. 24, 2026

Despite my romantic deficiencies, I gradually adjusted to township life, and began to develop a sense of inner strength, a belief that I could do well outside the world in which I had grown up.

From "Long Walk to Freedom" by Nelson Mandela

Related Words

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