1
as in incomplete
lacking some necessary part
a diet deficient in calcium can lead to weak bones
Synonyms & Similar Words
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Antonyms & Near Antonyms
2
as in unacceptable
falling short of a standard
woefully deficient eyesight kept him out of military service
Synonyms & Similar Words
Antonyms & Near Antonyms
3
as in lacking
not coming up to an expected measure or meeting a particular need
too deficient in common sense to be trusted to stay by himself
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Antonyms & Near Antonyms
Example Sentences
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Recent Examples of deficient
All babies are born deficient in vitamin K, which is vital to blood clotting, and cannot form what are called clotting factors, or substances in the body that help stop bleeding naturally.
—
Mary Walrath-Holdridge, USA Today, 9 Dec. 2025
Shell production is beginning to expand, as aresubsystems for cruise missiles, drones, and other weapons, although the production of air defenses remains deficient.
—Jack Watling, Foreign Affairs, 11 Nov. 2025
Do a Soil Test Plant experts recommend testing garden soil at least once every 3 years to make sure the soil hasn’t become nutrient-deficient or developed a pH imbalance that may interfere with plant growth.
—Lauren Landers, Better Homes & Gardens, 8 Nov. 2025
Hamant, a California native in her senior year, was diagnosed with Stage 4 SMARCB1-deficient kidney cancer in April after suffering symptoms such as shortness of breath and a persistent cough, according to The Seattle Times.
—Paulina Dedaj, FOXNews.com, 7 Nov. 2025
See All Example Sentences for deficient
Mary Walrath-Holdridge, USA Today, 9 Dec. 2025
Shell production is beginning to expand, as aresubsystems for cruise missiles, drones, and other weapons, although the production of air defenses remains deficient.
—Jack Watling, Foreign Affairs, 11 Nov. 2025
Do a Soil Test Plant experts recommend testing garden soil at least once every 3 years to make sure the soil hasn’t become nutrient-deficient or developed a pH imbalance that may interfere with plant growth.
—Lauren Landers, Better Homes & Gardens, 8 Nov. 2025
Hamant, a California native in her senior year, was diagnosed with Stage 4 SMARCB1-deficient kidney cancer in April after suffering symptoms such as shortness of breath and a persistent cough, according to The Seattle Times.
—Paulina Dedaj, FOXNews.com, 7 Nov. 2025
See All Example Sentences for deficient
Recent Examples of Synonyms for deficient
Adjective
-
Performance alone is an incomplete metric.—
Julian Hayes II,
Forbes.com,
21 Jan. 2026
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There was also what looked to be a legal blindside hit by linebacker Mohamed Toure just as Mendoza was releasing a pass, which fell incomplete.—
Justin Williams,
New York Times,
20 Jan. 2026
Adjective
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The European Union’s defense commissioner raised the prospect of a 100-thousand strong European army in a January speech, an idea previously dismissed as unworkable and political unacceptable in the bloc.—
Clare Sebastian,
CNN Money,
22 Jan. 2026
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For a game as complex and fast-paced as professional football, this lack of year-round preparation is unacceptable.—
Steve Forbes,
Forbes.com,
22 Jan. 2026
Adjective
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Nothing undermines success like a lack of stability, and of course, a lacking quarterback.—
Troy Renck,
Denver Post,
9 Jan. 2026
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These are all signs of a lacking musclespan, whereas not noticing any difficulties in everyday tasks suggests a stronger trajectory.—
Erica Sloan,
SELF,
11 Dec. 2025
Adjective
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But on Saturday, there were reports that things were going wrong with inboxes being overloaded with unwanted messages.—
David Phelan,
Forbes.com,
25 Jan. 2026
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The Celtics prevailed despite being outscored 29-10 at the free-throw line — Brooklyn attempted 34 foul shots to Boston’s 16 — and finishing on the wrong end of a 58-41 rebounding margin.—
Zack Cox,
Boston Herald,
24 Jan. 2026
Adjective
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In actuality, the impact of cyber events is greatly increased by bad data governance, which includes excessive data collecting, inadequate access controls, and indefinite retention.—
Chuck Brooks,
Forbes.com,
22 Jan. 2026
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The most common reason African violets stop flowering is inadequate lighting.—
Lauren Landers,
Better Homes & Gardens,
22 Jan. 2026
Adjective
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According to Jabra’s research, 99% of knowledge workers say poor audio quality impacts their online meetings and call quality.—
Mark Sparrow,
Forbes.com,
21 Jan. 2026
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While the pandemic hit everyone all at once, the recovery from that jolt has taken place on two diverging tracks, with the well-off getting wealthier and the poor getting poorer.—
Allison Morrow,
CNN Money,
21 Jan. 2026
Adjective
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The limited safety data currently released by companies is insufficient for comprehensive, objective analysis; full, transparent datasets must be made public.—
Sara Lind,
New York Daily News,
23 Jan. 2026
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Johnson’s office said that the decision to not charge the officer should not be considered an endorsement of the shooting or behavior, instead saying insufficient evidence would not allow for charges to proceed.—
Ben Wheeler,
Kansas City Star,
23 Jan. 2026
Adjective
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The show could still include a government subplot, maybe some shadowy investigators poking their noses around, but as it was written, the military was just unforgivably lame.—
Erik Kain,
Forbes.com,
21 Jan. 2026
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If Newsom continues to reduce spending on services for the poor and resist new taxes, his lame-duck status could draw unaccustomed resistance in the Legislature.—
Dan Walters,
Mercury News,
15 Jan. 2026
Cite this Entry
“Deficient.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/deficient. Accessed 28 Jan. 2026.
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