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

In addition to higher oil and gas prices because of the Iran war, the AI buildout has struggled with an insufficient supply of computer chips, electronic equipment, and workers to put it all together. — ABC News, 20 Sep. 2026

Despite the pump station and four drains on his street, Peterman said the city's stormwater management systems were insufficient. — Steve Maugeri, CBS News, 19 Sep. 2026

He was convicted and sentenced to prison, but Colombia’s Supreme Court overturned his conviction after finding the evidence was insufficient to sustain it. — Antonio María Delgado, Miami Herald, 18 Sep. 2026

As a new research paper put it, recent breaches have been the result not of a developing superintelligence as some top AI leaders warn, but of insufficient technical guardrails leaving networks vulnerable. — Prashant Rao, semafor.com, 18 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