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

The judge found the evidence insufficient to prove guilt beyond a reasonable doubt, resulting in acquittal on all counts. —Sarah Rumpf-Whitten, FOXNews.com, 29 Mar. 2026

Aaron thought about writing an op-ed or speaking at a rally, but such gestures struck him as painfully insufficient. —Oriana Van Praag, New Yorker, 28 Mar. 2026

Kratom poisonings are probably underestimated due to the reliance on self-reports and because of insufficient testing, the study researchers and other experts agreed. —Kristen Rogers, CNN Money, 27 Mar. 2026

The decline in enrollment has been attributed to lower birth rates, rising housing costs and what some criticize as insufficient state funding. —Jessica Ma, Dallas Morning News, 27 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