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

On Monday afternoon, seven state Assembly members and two state senators issued a statement calling on the board to delay the vote, echoing criticism from Uber that the public had insufficient time to consider it or the reasoning behind the change. —Karen Garcia, Los Angeles Times, 10 Mar. 2026

Several studies have linked insufficient sleep with numerous health problems. —Veronica Cristino, Vogue, 9 Mar. 2026

Worsley argues that Austen’s perfunctory treatment of her romantic endings hint that the men themselves, no matter how charming, are insufficient to guarantee marital bliss. —Literary Hub, 9 Mar. 2026

Potential eligibility issues included their work not being covered by unemployment insurance, voluntary departures from their job, termination for misconduct, insufficient past work, and previously exhausting benefits. —Jacqueline Munis, Fortune, 9 Mar. 2026

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