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)
Looking to grow your vocabulary? Check out this interactive, curated word list from our team of English language specialists at Vocabulary.com – one of over 17,000 lists we've built to help learners worldwide!
Martin Luther King Jr.'s "I Have a Dream" Speech (1963)
Interested in learning more words like this one? Our team at Vocabulary.com has got you covered! You can review flashcards, quiz yourself, practice spelling, and more – and it's all completely free to use!
Bridge to Terabithia
Want to remember this word for good? Start your learning journey today with our library of interactive, themed word lists built by the experts at Vocabulary.com – we'll help you make the most of your study time!
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.
Supplements may also be recommended where dietary intake is insufficient.
From Science Daily • Jun. 25, 2026
These include insufficient staffing, and the inability of staff to carry out basic and often mandatory training.
From BBC • Jun. 24, 2026
"We found insufficient evidence to conclude that exposure to the Act had any early substantial effects on social media use among adolescents aged under 16," the researchers wrote.
From Barron's • Jun. 24, 2026
Crowley’s lawsuit points to a televised debate May 6 in which she claims Bass blamed her for inoperable fire engines, which the former chief says were not repaired due to insufficient funding for mechanics.
From Los Angeles Times • Jun. 23, 2026
If there is less than a certain critical amount of matter in the universe, the gravitation of the receding galaxies will be insufficient to stop the expansion, and the universe will run away forever.
From "Cosmos" by Carl Sagan
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.
