From Longman Dictionary of Contemporary Englishstep down (also step aside) phrasal verbLEAVE A JOB OR ORGANIZATIONto leave your job or official position, because you want to or because you think you should Morris should step aside until the investigation is completed. as Eve Johnson has stepped down as chairperson. from He was forced to step down from his post. → step→ See Verb table
Examples from the Corpus
step as• Meanwhile Janet Street-Porter is stepping down as editor of the Independent on Sunday.• Mr Orlando was forced to step down as mayor despite his popularity with the voters.• He was due to step down as Oceania president in 2002.• House Democrats called a series of news conferences calling on Gingrich to step down as speaker.• If the panel brings formal charges, Gingrich may be forced to step down as speaker.• He stepped down as White House chief of staff in 1994 after a series of White House snafus.From Longman Business Dictionarystep down (also step aside) phrasal verb [intransitive]HUMAN RESOURCES to leave your job or official position asEve has stepped down as chairperson.The director is stepping down in favour of a younger man. → step→ See Verb table 