Syllable division derived from spelling — this word is not in the pronouncing dictionary, so no phonetic transcription is shown rather than a guessed one.
uncousinly is an adjective meaning "not befitting a cousin". It carries one recorded sense.
not befitting a cousin
Definitions, synonyms and semantic relations for uncousinly come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.