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