lavatio

If this was the case, each semi-circular recess just described was a _calda lavatio, balneum or labrum_.

The Excavations of Roman Baths at Bath Charles E. Davis

Under a constant rain of flowers the silver statue of Cybele was taken to the river Almo and bathed and purified according to an ancient rite (_lavatio_).

The Oriental Religions in Roman Paganism Franz Cumont