unacceptable

adjective

un·​ac·​cept·​able ˌən-ik-ˈsep-tə-bəl 

-ak-

: not acceptable : not pleasing or welcome

unacceptability

ˌən-ik-ˌsep-tə-ˈbi-lə-tē 

noun

unacceptably

ˌən-ik-ˈsep-tə-blē 

adverb

Synonyms of unacceptable

• wrong
• poor
• lame
• bad
• horrible
• terrible
• deficient
• awful
• unsatisfactory
• flawed
• disastrous
• pathetic

Examples of unacceptable in a Sentence

a word that is unacceptable in formal English

Some of her ideas were unacceptable to other people.

Recent Examples on the Web

Custard said, for the public, all this adds up to unacceptable risk. — Yuki Noguchi, NPR, 20 Aug. 2026

But to build a web of accusations based on false premises and the manipulation of reality in order to attack the Biennale and a film invited to compete is a petty and unacceptable act. — John Bleasdale, Variety, 19 Aug. 2026

Its expansion to defendants accused of violent crimes creates an unacceptable risk to our communities. — Eileen Burke, Chicago Tribune, 19 Aug. 2026

My behavior at last night’s Academy Awards was unacceptable and inexcusable. — Leigh Blickley, Entertainment Weekly, 13 Aug. 2026

Word History

First Known Use

15th century, in the meaning defined above

Rhymes for unacceptable

• acceptable
• perceptible
• susceptible
• imperceptible

Kids Definition

unacceptable

adjective

un·​ac·​cept·​able ˌən-ik-ˈsep-tə-bəl 

-ak-

: not acceptable : not pleasing or welcome

unacceptably

-blē 

adverb