Green’s Dictionary of Slang

1. to snub, to ignore, to treat disdainfully.

1899		W.J. Kountz Billy Baxter’s Letters 🌐 We also sent a copy to His Royal Highness, Albert, Prince of Wales, and, having heard nothing from him, it now looks as though Al were going to snob us.
1965		C. Brown Manchild in the Promised Land (1969) 223: He started snobbing the old crowd.
1981		J. Bradner Danny Boy 100: The Portugees in good jobs snob them who live in Albuoystown, and the former, in turn, is snobbed by the high-brows.
1983		Totally True Diaries of an Eighties Roller Queen 🌐 20 Sept.–2 Nov. At the end of the dance I said goodbye to him and he just snobbed away and didn’t say a word. I tried calling him the rest of the weekend but he wasn’t home.

2. (US) to associate with upper-class people.

1960		G. Swarthout Where the Boys Are 9: A lot of them go to Bermuda and Nassau to snob around.
2010		K. Richards Life 202: Suddenly we were being courted by half the aristocracy [...] I’ve never known if they were slumming or we were snobbing.