Here’s an architectural feature to spot as you watch football (soccer) today, Boxing Day in the UK, and American football over the weekend.
Vomitory refers to the large exit/entrance openings within the seating to concourses in older stadiums (e.g., Rose Bowl (stadium) [wikipedia]) and field-level openings in most newer stadiums that teams run back through to the locker rooms. See Vomitorium [wikipedia] for more.
The term is still at several spots in the building code, specifically related to access and exiting in Chapter 10.
(From the every increasing series of definition posts from the 2,300 page, 1975 Webster’s New Century, Second Edition, unabridged dictionary.