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Synonyms

insufficient

American  
[in-suh-fish-uhnt] / ˌɪn səˈfɪʃ ənt /

adjective

  1. not sufficient; lacking in what is necessary or required.

    an insufficient answer.

    Synonyms:
    deficient, scanty, inadequate
  2. deficient in force, quality, or amount; inadequate.

    insufficient protection.


insufficient British  
/ ˌɪnsəˈfɪʃənt /

adjective

  1. not sufficient; inadequate or deficient

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Other Word Forms

Derived 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.

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Vocabulary lists containing insufficient

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.

Insufficient airflow control can prevent the vortex from forming, causing the fire to behave more like a conventional burn.

From Science Daily • Jun. 5, 2026

Insufficient memory results in high-powered chips sitting idle, despite all their processing speed, as they wait to recruit extra memory from nearby chips.

From The Wall Street Journal • Apr. 28, 2026

Insufficient information impacts Texas’s ability to fully understand flood risks statewide.

From Salon • Jul. 22, 2025

Insufficient access to information in Spanish and low political efficacy keep the community from fruitful civic engagement.

From Seattle Times • Apr. 16, 2024

Insufficient though it is, it still comes at a high price.

From "Class Matters" by The New York Times

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