unbelievable

adjective

un·​be·​liev·​able ˌən-bə-ˈlē-və-bəl 

: too improbable for belief

The plot is unreal and unbelievable.

also : of such a superlative degree as to be hard to believe

the destruction was unbelievable

made an unbelievable catch in center field

unbelievably

ˌən-bə-ˈlē-və-blē 

adverb

Synonyms of unbelievable

• incredible
• incredulous
• impossible
• unlikely

Examples of unbelievable in a Sentence

a completely unbelievable story about why there was lipstick on his collar

Recent Examples on the Web

From unbelievable nonfiction to childhood favorites, these classics are worth adding to your home library. — Karen Brewer Grossman, Southern Living, 25 June 2026

At the same time, AI means spammers flooding the zone with unbelievable efficiency. — Danielle Chemtob, Forbes.com, 23 June 2026

Micron’s nearly unbelievable trajectory in just a year is due overwhelmingly to data-center demand, the company said. — The Editorial Board, Chicago Tribune, 26 June 2026

Druski also promised some unbelievable surprise performers during Culture’s Biggest Night. — Mikey Fresh, VIBE.com, 26 June 2026

Word History

First Known Use

1548, in the meaning defined above

Rhymes for unbelievable

• achievable
• believable
• conceivable
• perceivable
• receivable
• retrievable
• inconceivable
• irretrievable

Kids Definition

unbelievable

adjective

un·​be·​liev·​able ˌən-bə-ˈlē-və-bəl 

1

: too unlikely for belief

an unbelievable story

2

: very significant or impressive

made an unbelievable catch in center field

unbelievably

-blē 

adverb