anteroom
noun [ C ] formal uk/ˈæn.ti.ruːm/ /ˈæn.ti.rʊm/ us/ˈæn.t̬i.ruːm/ /ˈæn.t̬i.rʊm/ (also antechamber)
（通往较大、较重要房间的）前厅，接待室，候见室
a small room, especially a waiting room, that leads into a larger, more important room
The ministers waited for their meeting in the Cabinet anteroom. 部长们在内阁接待室等着开会。
Compare: lobby nounhallvestibule