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

Cooling tends to be a problem, too, with insufficient airflow across radiators, and obviously engine power is reduced with less oxygen to burn. — Jonathan M. Gitlin, ArsTechnica, 2 Nov. 2026

Policyholders must monitor funding and charges because insufficient cash value can cause coverage to lapse. — Aly J Yale, CBS News, 2 Nov. 2026

Several of our benchmarks wouldn't run due to hardware limitations, from a lack of ray tracing support in 3DMark's Solar Bay to insufficient memory for Steel Nomad. — Charles Jefferies, PC Magazine, 31 Oct. 2026

The Sacramento County district attorney’s office declined to file charges, citing insufficient evidence. — Los Angeles Times, 29 Oct. 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