Green’s Dictionary of Slang

butter-and-egg man n.

also butter-and-egger, butter and egg salesman, butter and milk man
[the dairy products such men often sold. The term was popularized by the nightclub owner Marie Louise ‘Texas’ Guinan (1884–1933), otherwise celebrated for her invariable greeting, ‘Hello sucker!’ Columnist Walter Winchell attributed the term to master of ceremonies Harry Richman, while the original ‘butter-and-egg man’ was supposedly ‘Uncle Sam’ Balcon, a New York provisioner. The term was further popularized first by Louis Armstrong’s song ‘The Butter-and-Egg Man’ (1924) and George S. Kaufman’s similarly named play of 1925]

1. (US) a prosperous farmer or small-town leading citizen who comes to the big city and poses embarrassingly as a playboy.

[US]O.O. McIntyre New York Day by Day 10 Dec. [synd. col.] They are the boys below the scale of the heavy sugar papas and butter and egg men and are designated bracelet buyers.
[US]Louis Armstrong & A. May [song title] Big Butter and Egg Man.
[US]J.P. McEvoy Showgirl 13: I could walk around with a lot of rhinestones on and look sneerful at all the big butter-and-eggers out front.
[US](con. late 1920s) L. Hughes Little Ham Act II: tiny: Who you goin’ with, Sugar Lou? sugar lou: A new hot papa [...] that is, if I can sneak away from my butter and egg man.
[US]Pittsburgh Courier (PA) 26 Feb. 11/1: Marshall Miles, Della’s big butter and milk man from Buffalo.
[US]Mezzrow & Wolfe Really the Blues 69: He puffed on the big cigar [...] and posed back like a big butter-and-egg man.
[Aus]Advertiser (Adelaide) 28 Jan. 2/6: We have been cast as big butter and egg men, boastful, money-proud, bloated and meddlesome.
[US]R. Chandler Playback 71: Cynical as a Park Avenue pet after her butter and egg man goes home.
[US]Wentworth & Flexner DAS.
[US](con. early 1950s) J. Peacock Valhalla 414: I’m women’s answer to the butter-and-egg man.
[US](con. 1968) D.A. Dye Citadel (1989) 91: Jesus. Another butter and egg salesman from Cornshuck.
[US]I.L. Allen City in Sl. (1995) 77: A special variety of the big spender was the (big) butter-and-egg man. He was a national social type, one of those out-of-town businessmen who showered night clubs with money. He always seemed to be from the Middle West and rich from a prosperous dairy business.
[US]M. Abbott Die a Little (2008) 227: Don’t want to lose the butter and egg man.

2. in attrib. use of sense 1.

Waukesha Dly Freeman (WI) 12 Apr. 3/2: Friends are trying to get up a stir for the butter-and-egg candidate [...] just in time to catch the farmers’ gathering.