Syllable division derived from spelling — this word is not in the pronouncing dictionary, so no phonetic transcription is shown rather than a guessed one.
unaccepted is an adjective meaning "not conforming to standard usage". It carries one recorded sense.
not conforming to standard usage
“the following use of `access' was judged unacceptable by a panel of linguists; `You can access your cash at any of 300 automatic tellers'”
linguistics
Definitions, synonyms and semantic relations for unaccepted come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.