deficiency
noun
de·fi·cien·cy
di-ˈfi-shən-sē 
plural deficiencies
1
: the quality or state of being defective or of lacking some necessary quality or element : the quality or state of being deficient : inadequacy
suffers from a deficiency of critical thinking
2
: an amount that is lacking or inadequate : shortage
staffing deficiencies
: such as
a
: a shortage of substances necessary to health
a vitamin C deficiency
hormone deficiencies
b
genetics
: deletion sense 2b(1)
Examples of deficiency in a Sentence
The disease may be caused by nutritional deficiencies.
The book's major deficiency is its poor plot.
a deficiency of vitamin C
There are several deficiencies in his plan.
The accident was caused by deficiencies in the engine.
Recent Examples on the Web
Key Takeaways Both iron and vitamin D can influence energy levels, but iron deficiency tends to have a more direct effect on fatigue.
—
Sara Hoffman, Verywell Health, 18 June 2026
Rossi, who was not involved with the research, said sunscreen causing vitamin D deficiency is a narrative that has been rampant on social media.
—Lily Alvino, NBC news, 18 June 2026
The safety board has issued six recommendations to address the regulatory oversight, technical standards for submersibles, and the safety management deficiencies.
—Ayesha Ali, ABC News, 17 June 2026
Or is there really a calorie deficiency, as well as everything else?
—David Frum, The Atlantic, 17 June 2026
See All Example Sentences for deficiency
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Sara Hoffman, Verywell Health, 18 June 2026
Rossi, who was not involved with the research, said sunscreen causing vitamin D deficiency is a narrative that has been rampant on social media.
—Lily Alvino, NBC news, 18 June 2026
The safety board has issued six recommendations to address the regulatory oversight, technical standards for submersibles, and the safety management deficiencies.
—Ayesha Ali, ABC News, 17 June 2026
Or is there really a calorie deficiency, as well as everything else?
—David Frum, The Atlantic, 17 June 2026
See All Example Sentences for deficiency
Cite this Entry
“Deficiency.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/deficiency. Accessed 19 Jun. 2026.
Copy CitationKids Definition
deficiency
noun
de·fi·cien·cy
di-ˈfish-ən-sē
plural deficiencies
1
: the quality or state of being deficient
2
: the quality or state of being inadequate
especially
: a shortage of substances necessary to health
Medical Definition
deficiency
noun
de·fi·cien·cy
di-ˈfish-ən-sē
plural deficiencies
1
: a shortage of substances (as vitamins) necessary to health
2
: deletion
Legal Definition
deficiency
noun
de·fi·cien·cy
di-ˈfi-shən-sē
plural deficiencies
: an amount that is lacking or inadequate: as
a
: the difference between the amount of tax owed and the amount of tax paid
b
: the difference between the amount owed under a security agreement and the amount the creditor is able to recover upon default of the debtor by selling the collateral
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