masturbatorium

masturbate +‎ -ium, probably by analogy with words like auditorium and sanatorium.

• (General American) IPA^(key): /ˌmæstɜː(ɹ)bəˈtɔːɹi.əm/
• Hyphenation: mas‧tur‧ba‧tor‧i‧um

masturbatorium (plural masturbatoriums)

1. (US, rare) A room in which a person masturbates; for example, a private room in a clinic where a sperm donor masturbates to produce semen.
   • 2002, Augusten Burroughs, Running with Scissors, St. Martin's Publishing Group, published 2010, →ISBN, page 313:

     As for the rape, well, Dr. Finch did seem like a pretty horny old fat man. I thought back to his masturbatorium, his many “wives.”

   • 2014, Ben Lerner, 10:04, Farrar, Straus and Giroux, →ISBN, page 126:

     The distinguished female author and I were now unabashedly getting drunk. As we ate, I told her the story of my visit to the masturbatorium, and I had her cracking up; we were laughing loudly enough to draw some stares from other tables.

   • [2018 July 25, Nellie Bowles, “The Dawning of Sperm Awareness”, in The New York Times‎, →ISSN:

     At his clinic, sports are on TV in the waiting room, and the walls are painted dark. The room Dr. Turek calls the “masturbatorium” has a lava lamp, framed Playboy magazines and a photo of a vintage Maserati (his own).]