Syllable division derived from spelling — this word is not in the pronouncing dictionary, so no phonetic transcription is shown rather than a guessed one.
obnoxiously is an adverb meaning "in an obnoxious manner". It carries one recorded sense.
in an obnoxious manner
“he said so in one of his more offensively intellectually arrogant sentences”
Definitions, synonyms and semantic relations for obnoxiously come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.