Lewis Short
amphĭthălămŏs (noun M) = ἀμφιθάλαμος:
* An antechamber: quorum (cubiculorum) unum thalamos, alterum amphithalamos dicitur,Vitr. 6, 10 Rose and Müll. (al. antithalamus, a chamber opp. to the sleeping-chamber).
Charlton T. Lewis, Charles Short, A Latin Dictionary