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 risks have only grown, so testing is good but clearly insufficient. — Kamal Ahmed, Fortune, 28 Sep. 2026

However, hiring of CDC scientific staff and budget support for high-consequence pathogen programs are woefully slow and insufficient. — Daniel Jernigan, STAT, 26 Sep. 2026

The program offers a small but meaningful boost to the insufficient number of shelter beds. — Michael Cuglietta, The Orlando Sentinel, 25 Sep. 2026

Deep Research can gather additional material when the existing project sources remain insufficient. — New Atlas, 24 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