sidewalk alumni
n.pl.— «The real alumni are great fans, root for their school, and support it no matter what. Those here that yell the loudest…brag the most…then bail at the first sign of trouble…are what I call the “Sidewalk Alumni” wannabees at best.» —“Fans voice frustration with Carr after loss to Appalachian State” by ICE223 MLive.com (Michigan) Sept. 4, 2007. (source: Double-Tongued Dictionary)
Further reading
Ever thought there ought to be an English word for this or that phenomenon? Such holes in the language are called lexical gaps. A listener in Ontario, Canada, notes that English lacks a single word for the mistake voice-to-text programs make when...
Matt from Grand Rapids, Michigan, was puzzled when colleagues kept saying someone had stood up at a wedding, indicating that they’d been a member of the wedding party. The expression stood up in that sense is an Americanism going back about two...