Synonyms of unheard-of

unheard-of

adjective

ˌən-ˈhərd-ˌəv 

as in unprecedented

not known or experienced before

houses selling at unheard-of prices

Synonyms & Similar Words

• unprecedented
• novel
• strange
• unfamiliar
• new
• fresh
• original
• unknown
• unaccustomed
• unique
• innovative
• unconventional
• untried
• pioneering
• nontraditional
• unused
• trailblazing
• unworn
• pathbreaking

Antonyms & Near Antonyms

• old
• familiar
• hackneyed
• traditional
• conventional
• tired
• established
• time-honored
• warmed-over
• tried
• derivative
• imitative
• tried-and-true

Example Sentences

Recent Examples of unheard-of

This effort ultimately translated to a virtually unheard-of customer acquisition cost of less than one-half of one cent per new user. — Encyclopedia Britannica, 15 May 2026

The world has so many moving parts that extraordinary and even unheard-of things happen all the time. — Faye Flam, Scientific American, 7 May 2026

This is a monumental and often impossible moment for media companies, when the corporate leaders who control them have been put under unprecedented government pressure even as the rhetoric from all quarters rises to unheard-of levels. — Steven Zeitchik, HollywoodReporter, 27 Apr. 2026

In an age where most electrics are looking towards the future with unheard-of modern tech on board, the C6 sports a WWII-era girder-style front fork and a monoshock with an internal floating piston at the rear. — New Atlas, 15 Apr. 2026