[vom-i-tawr-ee-uh m, -tohr-]
Origin of vomitorium
First recorded in 1745–55, vomitorium is from the Late Latin word vomitōrium
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
1754, "passage or opening in an ancient amphitheater, leading to or from the seats," from Latin (Macrobius, Sat., VI.iv); see vomit. Erroneous meaning "place where ancient Romans (allegedly) deliberately vomited during feasts" is attested from 1923.
Online Etymology Dictionary, © 2010 Douglas Harper