Green’s Dictionary of Slang

1. (US) to die or disappear; thus stepped out adj., dead.

1844		Yale Literary Mag. IX 381: Of the other pieces [...] which have been sent us, some will be found in the present number [...] and the remainder have ‘stept out’ [DA].
1851		‘Last Bloody Duel Fought in Ohio’ in T.A. Burke Polly Peablossom’s Wedding 177: Ay, dead! – stepped out! – dddead as Tecumseh!
1885		Bulletin (Sydney) 17 Oct. 12/1: Knowing the ‘old ’un’ would have to ‘step out’ soon, this practical youth put in his spare time working at a gorgeous coffin.
1902		A.D. McFaul Ike Glidden 277: That is why he stepped out when he did [DA].

2. (orig. US black) to go to a party, dance or some form of entertainment; note attrib. use in cit. 1997.

1907		‘Mark Twain’ Captain Stormfield 44: I thought what a figure I should cut stepping out amongst the redeemed in such a rig [DA].
1923		H.C. Witwer Fighting Blood 106: All my life I had wanted to have two suits of clothes – one for every day and one for when I’m stepping out.
1936		K. Mackenzie Living Rough 133: I know a swell speakeasy [...] how about stepping out Saturday night?
1941		J.M. Cain Mildred Pierce (1985) 343: Then it’s a date. That’s what we’ll do. We’ll step out.
1957		D. Niland Call Me When the Cross Turns Over (1958) 106: Listen, matey, how about you and me stepping out tomorrow night? There’s a good picture on at the Majestic.
1997		N. Barlay Curvy Lovebox 133: Don’t look any better in your steppin’ out garms.

3. (US, also step around) to escort or go out with someone socially; usu. as step out with.

1927		F.M. Thrasher Gang 222: The leader of our gang was what is usually termed a ‘hard rock.’ He was the leader because he was the ‘hardest’ .
1930		M. West Babe Gordon (1934) 136: Who’s steppin’ around?
1937		R. Westerby Wide Boys Never Work (1938) 150: You and me can step out sometimes, I s’pose, can’t we?
1945		A. Kober Parm Me 33: I bet you been stepping out with some girls.
1964		B. Jackson Get Your Ass in the Water (1974) 98: You can pick up on me ’most any old day / when me and my new old lady step out to play.
1989		M. Amis London Fields 281: Are you free any night this week? I thought we might step out together.
1999		Observer Mag. 3 Oct. 24: Martin started stepping out with Shirlie.

4. (US) to present oneself, to appear as.

1971

B. Short Black and White Baby 99: Arthur Lee Simpkins [...], who later stepped out as a single performer [...] made quite a career for himself on the West Coast.

5. (US) to take work with someone other than one’s primary employer.

2002

R. Gordon Can’t Be Satisfied 343: [O]nly Muddy was signed to Chess, so [the band] were free to step out.