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

In the lead-up to the 2022 vote, Jair Bolsonaro repeatedly cast unfounded doubts on Brazil's electronic voting system. — Arkansas Online, 4 Oct. 2026

Alito’s concerns are not unfounded, as threats to members in recent history have raised alarm about justices’ safety. — Claire Carter, The Washington Examiner, 4 Oct. 2026

To the broadcast crews, the fans were guilty until proven innocent, helping perpetuate the unfounded label that Fever fans were hateful, unruly and even discriminatory. — Jon Root Outkick, FOXNews.com, 3 Oct. 2026

In the lead-up to the 2022 vote, Jair Bolsonaro repeatedly cast unfounded doubts on Brazil’s electronic voting system. — Eléonore Hughes, Los Angeles Times, 3 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