Dictionary.com
Thesaurus.com
Showing results for insufficient. Search instead for twice-sufficient.
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

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.

Keep Reading on Vocabulary.com

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.

See Examples For:

He faces three felony counts of grand theft by embezzlement and one felony count of insufficient checking funds.

From Los Angeles Times Jul. 21, 2026

As for the weakest themes, UBS flagged consumer staples and consumer discretionary, citing macroeconomic worries and insufficient earnings revisions.

From MarketWatch Jul. 15, 2026

Asked if this was the offer Farage rejected because he felt it was insufficient, Jenrick replied: "That's right. Yes that's right."

From BBC Jul. 14, 2026

An independent probe concluded that the school’s response was insufficient and that it wasn’t clear who was handling allegations of wrongdoing.

From The Wall Street Journal Jul. 14, 2026

I have to make amends for being insufficient.

From "The Girl on the Train" by Paula Hawkins

Vocabulary.com logo
by dictionary.com

Dictionary.com's Learning Companion

Go beyond just looking up words.
Remember them forever with VocabTrainer.

Start training