de·fi·cient
di-ˈfi-shənt 
1
: lacking in some necessary quality or element
deficient in judgment
bones deficient in calcium
2
: not up to a normal standard or complement (see complement entry 1 sense 1b(1)) : defective
deficient strength
… rusted and aging pipes … abetted by deficient maintenance and sabotage.—
Adam Nossiter
Adam Nossiter
deficiently
adverb
Examples of deficient in a Sentence
Adjective
Several bridges in the city are structurally deficient.
a diet deficient in calcium can lead to weak bones
Recent Examples on the Web
Jerry McDonald, Mercury News, 16 Oct. 2025
At least 1,235 miles of the city’s sidewalks, or about 40%, are considered deficient.
—Elliott Wenzler, Denver Post, 15 Oct. 2025
Hannah Yasharoff, USA Today, 20 Aug. 2025
Numbness and Tingling in Extremities Being calcium deficient can impact nerves, especially those in your hands and feet.
—Cristina Mutchler, Verywell Health, 11 June 2025
See All Example Sentences for deficient
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Adjective
In the meantime, Jones has been carrying a run-deficient offense to the tune of 313 yards per game — the most in the NFL.
—Jerry McDonald, Mercury News, 16 Oct. 2025
At least 1,235 miles of the city’s sidewalks, or about 40%, are considered deficient.
—Elliott Wenzler, Denver Post, 15 Oct. 2025
Noun
Those who are iron deficient, pregnant, breastfeeding, allergic to mint and/or who are taking certain medications such as ones that slow blood clotting or medications for diabetes should avoid it, unless their healthcare provider suggests otherwise, Davis recommends.
—Hannah Yasharoff, USA Today, 20 Aug. 2025
Numbness and Tingling in Extremities Being calcium deficient can impact nerves, especially those in your hands and feet.
—Cristina Mutchler, Verywell Health, 11 June 2025
See All Example Sentences for deficient
Cite this Entry
“Deficient.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/deficient. Accessed 31 Oct. 2025.
Copy CitationMedical Definition
deficient
adjective
de·fi·cient
di-ˈfish-ənt
1
: lacking in some necessary quality or element
a deficient diet
When the body is deficient in vitamin C, these small blood vessels become fragile and break easily, causing small, bright red spots to appear around the hair follicles.—Erica Julson, Healthline
Erica Julson, Healthline2
: not up to a normal standard or capacity
deficient strength
Deficient sleep, which includes not getting enough sleep, irregularly timed sleep, poor quality sleep, and/or sleep disorders, impacts all aspects of functioning, including physical, emotional and occupational.—Hailey Meaklim et al., Sleep Health
Hailey Meaklim et al., Sleep Health3
: having, relating to, or characterized by a genetic deletion or alteration
… cancer cells that are deficient for the tumor suppressor gene p53 can be outcompeted by cells in which p53 is still intact.—Stephano Mello and Dirk Bohmann, eLife
Stephano Mello and Dirk Bohmann, eLife… the deficient expression of a gene in the endometrium during the receptive phase … in infertile women.—S. Henriquez et al., Molecular Human Reproduction
S. Henriquez et al., Molecular Human Reproduction
deficiently
adverb
performed deficiently in clinical trials
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