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

• 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 former governor complained on June 19 that the Board of Elections' plans to mitigate the heat were insufficient and demanded air conditioning in polling places. —Ben Adler, USA Today, 24 June 2025

Even if the United States completes the modernization as planned, the country’s arsenal will still be insufficient to confront today’s and tomorrow’s nuclear challenges. —Vipin Narang, Foreign Affairs, 24 June 2025

Some stablecoins have drawn scrutiny in the past over concerns that their reserves were insufficient or relied on mechanisms that would unreliable in times of market stress. —Jesse Pound, CNBC, 21 June 2025

Some health experts think that the current federal recommendation is insufficient. —Lila Shroff, The Atlantic, 20 June 2025

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