Syllable division derived from spelling — this word is not in the pronouncing dictionary, so no phonetic transcription is shown rather than a guessed one.
brain-worker is a noun meaning "someone whose profession involves using his head to solve problems". It carries one recorded sense.
someone whose profession involves using his head to solve problems
Definitions, synonyms and semantic relations for brain-worker come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.