deficiency
Americannoun
-
the state of being deficient; lack; incompleteness; insufficiency.
- Synonyms:
- scarcity, paucity, inadequacy, shortage
-
the amount lacked; a deficit.
noun
-
the state or quality of being deficient
-
a lack or insufficiency; shortage
-
another word for deficit
-
biology the absence of a gene or a region of a chromosome normally present
Other Word Forms
Derived Forms
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.
Vocabulary lists containing deficiency
Freak the Mighty
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Flowers for Algernon
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Paltry Parlance: Synonyms for "Few"
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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.
Scientists have long known that animals tend to crave protein-rich foods when deprived of protein, but exactly how the body senses this deficiency remained unclear.
From Science Daily • May 28, 2026
This is why B12 deficiency is taken seriously.
From Science Daily • May 27, 2026
B12 is clearly essential for the nervous system, and deficiency should not be ignored.
From Science Daily • May 22, 2026
"In addition to redefining B12 deficiency, clinicians should consider supplementation in older patients with neurological symptoms even if their levels are within normal limits," she said.
From Science Daily • May 22, 2026
Campbell felt the deficiency all the more sharply between 1914 and 1918, when the Great War cut off all travel to Britain and the continent.
From "Big Science" by Michael Hiltzik
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
