Green’s Dictionary of Slang

1. (orig. US campus) used to emphasize the mediocre or mass-market quality of the combined n.

1984		Mason & Rheingold Slanguage n.p.: Mcmoon [‘moon’].
1990		S. Morgan Homeboy 159: They’re only here to bail out one of the McBimbos.
1999		Guardian Media 8 Nov. 2: There was hardly a newspaper editor who did not denounce it as the ‘Mac’ paper – journalism peddled as fast food.
1999		Indep. Rev. 10 Sept. 8: Vast new houses with marble swimming pools dubbed ‘McMansions’.
2000		Observer 5 Mar. 28: Global ‘McCulture’ is a tragedy.
2003		Eble Campus Sl. Nov. 5: mcfired – terminated in an embarrassing way from a low-paying job: You got mcfired from WallMart?
2005		E. White My Lives 223: I pictured them living in a McMansion on an acre and a half.
2012		news.com.au 30 Nov. 🌐 Demographer Mark McCrindle said despite forecasts of a McMansion glut in Australia [...] the McDonald’s of housing is a vision of things to come.
2017		Guardian 7 Oct. 🌐 Set against an ultra-bling backdrop of McMansions, beauty salons and champagne pool parties [etc].
2018		G. Gilmore Base Nature [ebook] [P]eering instead at the properties on the other side of the road, ugly McMansions set back from the cliffs.
2021		C. Hammer Opal Country 463: Torshack appears to be barricaded inside the grand house, the McMansion.

2. implying the obesity of those described.

2013

Independent 13 Apr. 🌐 ‘McPassengers’ to be offered extra-wide seats [...] European aircraft manufacturer Airbus is to offer [...] seats to cater for super-sized passengers.