the area of a theater or concert hall where the audience sits
"The speaker walked through the empty auditorium before the performance began."
a large room for public meetings or performances
"The university students gathered in the auditorium to watch the guest speaker's lecture."
In plain English: An auditorium is a large room with tiered seating where people gather to watch performances, listen to speeches, or attend lectures.
"The audience filled every seat in the large auditorium before the concert began."
Usage: An auditorium refers to a specific, enclosed space designed with tiered seating and acoustics optimized for speeches or concerts. Do not confuse this term with the general concept of an audience, which describes the people attending rather than the venue itself.
The word auditorium comes from the Latin term auditorium, which literally means "pertaining to hearing." It entered English as a noun describing a place designed for listening to speeches or music.