insufficient
Americanadjective
-
not sufficient; lacking in what is necessary or required.
an insufficient answer.
- Synonyms:
- deficient, scanty, inadequate
-
deficient in force, quality, or amount; inadequate.
insufficient protection.
adjective
Other Word Forms
Etymology
Origin of insufficient
First recorded in 1350–1400; Middle English, from Late Latin insufficient-, stem of insufficiēns; equivalent to in- 3 + sufficient
Explanation
If something is insufficient, it isn't enough. A high school diploma is very helpful for getting a job, but by itself, it's probably insufficient to land you a job as an astronaut. Something adequate is sufficient, and something inadequate is insufficient (in- meaning "not"). If you have $100 in the bank and you try to use a debit card for a $102 purchase, even though you’re close to having enough, your funds are insufficient to cover the sale. Anything that falls short of a required amount or expected measure is insufficient, whether it's the amount of air in a bike tire or the votes needed to win an election.
Vocabulary lists containing insufficient
Figurative Language in King's "I Have a Dream" Speech (1963)
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Martin Luther King Jr.'s "I Have a Dream" Speech (1963)
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Bridge to Terabithia
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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.
This occurs when blood supply to the front portion of the optic nerve becomes insufficient, potentially damaging the nerve and interfering with vision.
From Science Daily ● Oct. 15, 2026
On Tuesday, regulators announced a fine of $1.2 billion against Bank of America after finding that the bank had insufficient systems to monitor and report possible financial crimes.
From The Wall Street Journal ● Oct. 14, 2026
She also said the ophthalmology "capacity appears insufficient to meet the demand", adding that the absence of a national mechanism means those "requiring surveillance for ophthalmic conditions may experience prolonged delays".
From BBC ● Oct. 14, 2026
Because these thresholds were established in the 1980s and never adjusted, they’re already insufficient.
From MarketWatch ● Oct. 13, 2026
As Venkatesh would later tell his university colleagues, he realized that the multiple-choice answers A through E were insufficient.
From "Freakonomics: A Rogue Economist Explores the Hidden Side of Everything" by Steven D. Levitt
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Get a wordDefinitions 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.
