A.a public feast in memory of Theseus' uniting all the towns of Attica into a single city-state, celebrated on the 17th Boëdromion, Th.2.15, IG12.188.60 (prob.), St.Byz. s.v. Ἀθῆναι.
II. sg. συνοίκιον, τό, a joint lodging, Petron.93 (in Lat. form synoecium).