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