megamansion

plural megamansions

1. A very large mansion.

   The threat of some sort of development — ranchettes and megamansions, most likely — remained.

   2008 March 25, “Last Chapter in Yellowstone”, in New York Times

   1 more example

   McClean has been described time and time again as LA’s “megamansion king”, and no wonder. He’s famously the architect behind what’s being called “the most expensive house in America”.

   2021 January 30, Tanya Sweeney, “The Irish architect who became the ‘megamansion king’ of LA”, in The Irish Times