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