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-in is a noun meaning "short underpants for women or children (usually used in the plural)". It carries one recorded sense.
Definitions, synonyms and semantic relations for step-in come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.