Synonyms of the word

unacceptable

• adj. unsatisfactory; not acceptable.
• adj. (linguistics) not conforming to accepted usage.
• n. Something that is not acceptable.

exceptionable

• adj. Liable to cause disapproval, objection or debate.

impossible

• adj. Not possible; not able to be done or happen.
• adj. (colloquial, of a person) Very difficult to deal with.
• adj. (mathematics, dated) imaginary.
• n. (obsolete) an impossibility.

insufferable

• adj. Not sufferable; very difficult or impossible to endure.

intolerable

• adj. Not tolerable; not capable of being borne or endured; not proper or right to be allowed; insufferable;…
• adj. Extremely offensive or insulting.

nonstandard

• adj. Not standard.
• adj. (linguistics) Not conforming to the language as used by the majority of its speakers.
• n. Something that is not standard.

objectionable

• adj. Arousing disapproval; worthy of objection; offensive.

unaccepted

• adj. Not accepted; unacceptable.

unbearable

• adj. so unpleasant or painful as to be unendurable.

unendurable

• adj. Not to be endured; intolerable.

unsatisfactory

• adj. inadequate, substandard or not satisfactory.

unsufferable

• adj. Not able to be suffered, difficult or impossible to endure; insufferable.

unwelcome

• adj. Not welcome.