insufficient

adjective

in·​suf·​fi·​cient ˌin(t)-sə-ˈfi-shənt 

: not sufficient : inadequate

insufficient funds

especially : lacking adequate power, capacity, or competence

insufficient bandwidth

insufficiently adverb

Synonyms of insufficient

• lacking
• inadequate
• scarce
• low

Examples of insufficient in a Sentence

The case was thrown out because of insufficient evidence.

there's been an insufficient number of volunteers for the job, so I'll have to select someone

Recent Examples on the Web

Pondexter said that the University of Utah covered the cost of Jordan’s funeral and that her grandson had insufficient assets upon his death to warrant probate. —Daniel Libit, Sportico.com, 12 Dec. 2025

Counties where more people reported insufficient sleep tended to have lower life expectancy. —Khloe Quill, FOXNews.com, 12 Dec. 2025

Consuming sufficient dietary sources of zinc is essential for maintaining health, but when dietary sources are insufficient, a zinc supplement may be beneficial. —Amy Brownstein, Verywell Health, 11 Dec. 2025

The board initially tried to reduce spending only at the central office, but that approach proved insufficient. —Da Lin, CBS News, 8 Dec. 2025

Word History

Etymology

Middle English, from Anglo-French, from Late Latin insufficient-, insufficiens, from Latin in- + sufficient-, sufficiens sufficient

First Known Use

14th century, in the meaning defined above

Rhymes for insufficient

• beneficent
• coefficient
• inefficient
• deficient
• efficient
• omniscient
• proficient
• sufficient

Kids Definition

insufficient

adjective

in·​suf·​fi·​cient ˌin(t)-sə-ˈfish-ənt 

: not sufficient : inadequate

insufficiently adverb