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 absence of a crosswalk, together with insufficient lighting and the intersection's predictable pedestrian hazards, creates grounds for wrongful death lawsuits. —Matt Emma, USA Today, 8 May 2026

In this instance, the judges found the administration’s argument for the tariffs insufficient. —Elisabeth Buchwald, CNN Money, 7 May 2026

Stock trading bans are insufficient if members can still be bought through super PAC spending. —Lucas Robinson, San Diego Union-Tribune, 7 May 2026

The sources claimed staffing was insufficient and that staff members were poorly trained, and that an inability to handle the massive volume of patient and provider data jeopardized coverage for millions. —Jason Kane, NBC news, 6 May 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