As you might have guessed, this term doesn’t exactly derive from ancient Greek roots. The “Mc” must give it away. Yes, the prefix is referencing the ubiquitous cultural icon that is McDonald’s, the world’s fast food juggernaut. Therefore, McMansion is a derogatory “architectural term” used to describe the type of housing that started dominating the American suburban landscape in the 80s. Similar to a mansion, these homes are ridiculously oversized (dare we say “supersized””). Similar to the chain restaurant, they are everywhere (dare we say “mass produced””). Similar to fast food, their quality is not always appetizing (shall we say “McRib””). Yes, they’ll fill you up, but there’s not always a great deal nutritional / aesthetic / architectural value there to completely satisfy.
See also: plywood palazzo