Liable to be disapproved of and not pleasing or welcome: Jack's behavior in school was so unacceptable, that he was not only sent to the principal's office, but was sent home immediately.

Floyd's handwriting was so unacceptable that Mrs. Thompson couldn't decipher it, so he had to do his homework again under his teacher's supervision.

To repeat something; such as, facts, ideas, etc. without understanding them or explaining them: The speaker memorized the historical scientific names making unacceptable regurgitations of them during his speech; in other words, the he was just throwing out facts and figures without any relevant explanations or interconnections.