A.town-hall, residence, or office of chief magistrates, Hdt.4.62 (dub.), Lys.9.9, X.Cyr.1.2.3, Isoc.5.48, Arist.Mu.400b16; “τὰ ἀ. καὶ βουλευτήρια” D.10.53, cf. IG2.475.21, al., OGI268.18 (Nacrasa, iii B. C.), PGrenf.2.30, al. (ii B. C.).
2. τὰ ἀ. public records, archives, prob. in SIG684.7 (Dyme, ii B. C.), cf. D.H.2.26, PTeb.397.19 (ii A. D.).
II. college or board of magistrates, magistracy, Arist.Pol.1298b28, 1304a19: but in pl., special boards, ib. 1299a36, 1331a25, Plu.Ages.33; “ὀμόσαι τὰ ἀ.” IG2.332.45, cf. OGI218.149 (Ilium), etc.; “ὅσοι ἀρχείων μετέχουσιν καὶ δικαστηρίων” SIG286.20 (Milet., iv B. C.).
III. in the Roman camp, = principia, head-quarters, Plu.Galb.12.