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 facility is facing a federal lawsuit filed by the ACLU and other civil rights groups, which alleges serious operational failures—including raw sewage leaks, insect infestations, insufficient medical care, and inadequate food and clothing for cold weather. —Rosalio Ahumada, Sacbee.com, 5 Dec. 2025

The investigation noted that the hangar bay’s non-skid coating was insufficient, making the deck slippery. —MSNBC Newsweek, 5 Dec. 2025

Kirchner and others, who’d met in the PauseAI Discord server, thought that that genteel approach was insufficient. —Kaitlyn Tiffany, The Atlantic, 4 Dec. 2025

Over the past decade, the work has highlighted when and where there has been insufficient progress in boosting livelihoods and leadership opportunities for women and ethnic minorities. —Josefina Echavarria Alvarez, The Conversation, 3 Dec. 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