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