unfounded

adjective

un·​found·​ed ˌən-ˈfau̇n-dəd 

: lacking a sound basis : groundless, unwarranted

an unfounded accusation

Synonyms of unfounded

• unreasonable
• baseless
• groundless
• unsubstantiated
• unwarranted

Examples of unfounded in a Sentence

the accusation proved to be unfounded

Recent Examples on the Web

The pullback isn't totally unfounded given the problems in its medical devices business. — Kevin Stankiewicz, CNBC, 13 Oct. 2026

Its inclusion in the documentary has provided ammunition for Musk supporters and his lawyers to discredit the film, pointing to an unfounded conspiracy theory about SpaceX’s Starlink satellites interfering in the election. — ABC News, 12 Oct. 2026

Only 9 percent were substantiated; 52 percent were found either to be unfounded or to involve conduct within NYPD guidelines. — Daniel Edward Rosen, Washington Post, 8 Oct. 2026

Supporters of the rule change also spoke against the COVID vaccine and the measles, mumps and rubella vaccine (MMR), repeating unfounded claims, such as that doctors make money from vaccines and that vaccines cause autism. — Ana Goñi-Lessan, Sun Sentinel, 8 Oct. 2026

Word History

First Known Use

1648, in the meaning defined above

Rhymes for unfounded

• abounded
• astounded
• compounded
• confounded
• expounded
• foregrounded
• impounded
• propounded
• rebounded
• resounded
• subrounded
• surrounded

Kids Definition

unfounded

adjective

un·​found·​ed ˌən-ˈfau̇n-dəd 

ˈən-

: lacking a sound base : groundless

unfounded suspicions