Definition of "bouleuterion"

[…] we print here an updated and revised list of bouleuteria, some attested only in written sources, some physically preserved.63 In most cases, however, the identification of a building as a bouleuterion is uncertain.

1994, Mogens Herman Hansen, From Political Architecture to Stephanus Byzantius: Sources for the Ancient Greek Polis, Franz Steiner Verlag, page 38

The "Old Bouleuterion", whether it was built before or after the Persian sack of Athens,3 certainly antedates the New Bouleuterion.

1995, Michel Troper, Mikael M. Karlsson, Law, Justice and the State: Proceedings of the 16. World Congress of the International Association for Philosophy of Law and Social Philosophy: Reykjavík, 26 May - 2 June, 1993, page 135

The history of the bouleuterion as a distinct architectural form seems to begin in late Archaic Athens, where the first Bouleuterion was perhaps built soon after the constitutional reforms of Kleisthenes.

2006, Frederick E. Winter, Studies in Hellenistic Architecture, University of Toronto Press, page 142