Syllable division derived from spelling — this word is not in the pronouncing dictionary, so no phonetic transcription is shown rather than a guessed one.
arrhythmical is an adjective meaning "without regard for rhythm". It carries one recorded sense.
without regard for rhythm
Definitions, synonyms and semantic relations for arrhythmical come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.