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

Critics say such plans are wholly unacceptable because light pollution from so many large, bright satellites would radically degrade views of the night sky. — Mary Randolph, Scientific American, 16 July 2026

For the union, this is unacceptable and yet another issue their members are facing. — Carmela Karcher, CBS News, 14 July 2026

Democrats have called it an unacceptable gift from a foreign government that is barred by the Constitution, as what is called an emolument. — Bart Jansen, USA Today, 8 July 2026

Should England go on to win their quarterfinal or entire tournament, their run will be tainted by this scandal, forever laden with an asterisk over this unacceptable atrocity. — Ian Miller Outkick, FOXNews.com, 7 July 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