From Longman Dictionary of Contemporary Englishanterooman‧te‧room /ˈæntɪrʊm, -ruːm/ noun [countable] TBBa small room that is connected to a larger room, especially where people wait to go into the larger room SYN antechamber
Examples from the Corpus
anteroom• George Gardiner and Alfred Sherman sat in an anteroom ready at an instant to do her bidding.• There was an anteroom and an empty office on the other side of the disused primate facility.• Once-grand anterooms had been partitioned off.• He found himself in the semidarkness of a sort of anteroom.• The two men rose and went through the minister's anteroom into his main office.• The five-person group shared a single room, with a small anteroom to the side.• He rose from his desk and went through the anteroom into Shirley's office. 