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

Congested dormitories, a lack of emergency exits and insufficient firefighting equipment have often contributed to loss of life and extensive damage. —ABC News, 12 June 2026

The issue is not excessive thinking but insufficient engagement. —Bybryan Robinson, Forbes.com, 12 June 2026

Based on a review of multiple studies, there is currently insufficient evidence that everyone needs to cycle caffeine, per Examine. —Samantha Agate, Charlotte Observer, 11 June 2026

The outlet also reported that Dharod claimed that the past two years had seen decreased business, leading to insufficient revenue. —Chiara Kim, PEOPLE, 11 June 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