Lewis & Short

būleutērĭum (-on), ii, n., = βουλευτήριον, the place where the Greek senate assembled, the senate-house: in curiā Syracusis, quem locum illi buleuterium nomine appellant, Cic. Verr. 2, 2, 21, § 50: Cyzici et buleuterion vocant aedificium amplum sine ferreo clavo, etc., Plin. 36, 15, 23, § 100.