lavatorium

English Wikipedia has an article on:

lavatorium

Wikipedia

Borrowed from Late Latin lavātōrium. Doublet of lavatory.

lavatorium (plural lavatoriums or lavatoria)

1. (rare) A washroom or place.
   • 1903, Max Pemberton, chapter VII, in Doctor Xavier, 3rd edition, London: Hodder and Stoughton […], page 76:

     [T]he attendant returned and invited her to go to the lavatorium. Here the Japanese girls were waiting, and they at once took possession of Esther; and placing her beneath a refreshing spray of luke-warm water, they began to massage her.

   • 2010, Stephen Burrow, “Inviolable Protection”, in Buddleia Dance on the Asylum: A Nurse’s Journey through a Mental Hospital, Ely, Cambs.: Melrose Books, →ISBN, page 66:

     Tea break over, the next stage is the equivalent of the Roman lavatorium and all the patients are called for their communal washroom ablutions, only almost none of them volunteer themselves to wash, or shave. ‘Have you had the chance to shave anybody, yet?’ asks the Charge Nurse.

   • 2014, Ada Robinson, chapter 10, in The New Sword, [Adams Basin, N.Y.]: Wildflowers Books, →ISBN:

     Sakela wondered, not for the first time, at the city planning that placed the governor’s, constable’s and chief justice’s residences over the drains and left the heavily-used public lavatorium to the labor of the honey-wagon. The lavatorium was clean and the attendant held out a fresh cloth at the wash basin.

   1. Particularly, (architecture) the communal washing area in a monastery.
2. (rare) A lavatory.
   • 2015, Richard Graham, “The Fortress”, in Knight for a Day, London: Sagesse Press, →ISBN, page 48:

     A visit to the toilet proves embarrassing. Luke directs me to ‘the lavatorium’, a room with a long wooden bench that has four seats with holes the size of dinner plates.

   • 2017, Chris Young, “The Preamble and the First Few Days”, in Walk a Mile: Tales of a Wandering Loon, Newark, Notts.: Trigger Press, published 2018, →ISBN, page 234:

     So anyway, I began my journey meandering through the streets of Edinburgh, regretting the third cup of tea I’d had that morning. No matter, I thought, I know of a public lavatorium in Corstorphine (not a drug – actually an area of Edinburgh).

   • 2023, Christopher P. Menkhaus, “It’s Not a War”, in I Was a Teenage MILAB: A Novel, [Indianapolis, Ind.]: TimeAlpha Media, →ISBN, section ii:

     Before the dorm, we endured an equally enlightening and embarrassing hour and a half in the lavatorium, as they called it. All us boys were schooled in using the space-toilets, taking a space-shower, and brushing your space-teeth.

   1. (rare, historical fiction) An ancient Roman lavatory.
      • 1985, S. Sponte [pseudonym; David J. Millstein], “To Wit: Pro Bono Publico, and how he grew”, in The Pennsylvania Lawyer, volume 7, Harrisburg, Pa.: Pennsylvania Bar Association, page 38, columns 2–3:

        After that, Probono fades into obscurity, save for a reference in the third volume of Caesar’s Gallic Suits pertaining to an inscription engraved on a wall in a public lavatorium which, freely translated, means “Probono gives it away-call MXC-IIVD.”

      • 2008, Carolyn Hennesy, “Newly ‘Maid’”, in Pandora Gets Jealous, New York, N.Y.: Bloomsbury U.S.A. Children’s Books, →ISBN, page 18:

        They say that because he’s missing so much of his liver, he can’t digest his food like normal people and hasn’t been to the lavatorium in years. They say he’s gonna blow like a volcano.

      • 2010, Kate Quinn, chapter 11, in Mistress of Rome, London: Headline Review, →ISBN, page 164:

        He barely made it to the lavatorium, throwing up again and again.

      • 2014, Jeanne Willis, “Julius Teaser: The World’s Worst Prankster”, in Hysterical Historicals (TreeTops Chucklers), Oxford, Oxon: Oxford University Press, →ISBN, page 37:

        Do you need the lavatorium, Hilarious? I need to go.

      • 2015, Shoo Rayner, Stinkius Maximus (Roman Brit; 3)‎^[1], London: Hodder & Stoughton, →ISBN:

        “The heating is back on, but we’ve got a big problem with the lavatorium,” Bumptius explained. “The toilet drains are still blocked with frozen poo. […]”

English Wikipedia has an article on:

lavatorium

Wikipedia

lavō (“wash”) +‎ -tōrium.

lavātōrium n (genitive lavātōriī or lavātōrī); second declension

1. (architecture, Late Latin, Medieval Latin) A washroom or place, particularly a lavatorium.

Second-declension noun (neuter).

¹Found in older Latin (until the Augustan Age).

• “lavatorium”, in Charlton T. Lewis and Charles Short (1879) A Latin Dictionary, Oxford: Clarendon Press
• lavatorium in Charles du Fresne du Cange’s Glossarium Mediæ et Infimæ Latinitatis (augmented edition with additions by D. P. Carpenterius, Adelungius and others, edited by Léopold Favre, 1883–1887)