antechamber n. + Add to list US //ˈæntɛˌtʃeɪmbɝ// UK //ˈæntɪtʃˌeɪmbɐ// an·techam·ber SynonymsEtymology Synonyms anteroomfoyerhalllobbyvestibuleOriginFRMantichambre→ENantechamber From Middle French antichambre, with remodelling after ante- and chamber. By surface analysis, ante- + chamber.