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

Prevents Calcium Deficiency That Can Reduce Bone Strength Individuals with reduced calcium absorption or insufficient dietary intake may be at risk of calcium deficiency and may require a supplement. — Jennifer Lefton, Verywell Health, 3 Sep. 2026

But tariffs alone proved insufficient to tackle the security risks that come with Chinese monopoly power, and Washington has begun to experiment with many more tools of industrial policy. — Chad P. Bown, Foreign Affairs, 1 Sep. 2026

Prosecutors argued there was enough evidence against Tyler Robinson to proceed with the case, while defense attorneys maintained that the evidence was insufficient. — Daniel Arkin, NBC news, 1 Sep. 2026

And when strategic initiatives fail, the standard explanation points to poor planning, insufficient resources or unclear strategy. — Aurelien Mangano, Forbes.com, 1 Sep. 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