Syllable division derived from spelling — this word is not in the pronouncing dictionary, so no phonetic transcription is shown rather than a guessed one.
do-gooder is a noun meaning "someone devoted to the promotion of human welfare and to social reforms". It carries one recorded sense.
someone devoted to the promotion of human welfare and to social reforms
Definitions, synonyms and semantic relations for do-gooder come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.