| Word | Definitions | Synonyms |
|---|---|---|
| unacceptably | (adverb) to an unacceptable degree | Synonyms: intolerably |
| unaccompanied | (adverb) without anybody else or anything else | Synonyms: alone, solo |
| unaccountably | (adverb) in an unaccountable manner | - |
| unachievably | (adverb) in an unattainable manner or to an unattainable degree | Synonyms: unattainably |