sideroom
nounUK /ˈsaɪd.ruːm/
US /ˈsaɪd.ruːm/
A side room is a small extra room next to the main room.
The waiter led us to a quiet sideroom for the birthday party.
OTHER MEANINGS
2. A small room attached to a larger hall, often used for storage or private meetings.
The committee met in the sideroom while the main hall was being cleaned.
3. A minor or subordinate room in a building, not part of the main living area.
The old house had a sideroom off the kitchen that served as a pantry.
4. A separate compartment or bay beside a main area, as in a theater or studio.
The actors waited in the sideroom until their cue.