A.building, house, dwelling, Hdt.1.17,114, etc. ; “ἡ οἰκία ἡ δημοσία” IG12.94.36 ; οἰκία ἱερά ib.363.24; κατ᾽ οἰκίαν at home, Pl.La.180d ; “ἰδίᾳ καὶ κατ᾽ οἰκίας” Id.Lg. 788a ; ἔτυχεν ἐπὶ τῆς οἰ. was at home, X.Eph.5.4 : in Com. and Attic Prose much more freq. than οἶκος : sts. opp. οἶκος as house to set of apartments or room, “τᾶν οἰκιᾶν τιμὰν κομιζέσθω τῶ οἴκω ἑκάστω δύο μνᾶς” SIG306.16 (Tegea, iv B. C.), cf. PTeb.46.9 (cf. 18) (ii B. C.), 38.14, 15 (ii B. C.), PFay.31.11 (ii A. D.).
2. in Att. law, οἶκος was distd. from οἰκία, the former being the property left at a person's death, his estate, the latter the dwelling-house only, as stated by X.Oec.1.5, cf. Hdt.7.224, Jul.Gal.Fr.12, etc.
II. household, domestic establishment, Pl.Grg.520e ; δὔ οἰκίας ᾤκει, i. e. he kept two establishments, D.39.26, cf. Arist.Pol.1265b26 ; more primitive than the πόλις, ib.1252b17, EN1162a18, al. ; ὁ ἐπὶ τῆς οἰκίας the house-steward, PCair.Zen.150.16 (iii B. C.).
III. the household, i. e. inmates of the house, Pl.Lg.909b (pl.).
IV. house or family from which one is descended, “οἰκίης ἀγαθῆς” Hdt.1.107 ; οἰκίης οὐ φλαυροτέρης ib.99 ; “οἰκίης οὐκ ἐπιφανέος” Id.2.172 ; “τῇ Κύρου οἰκίῃ συγγενέες” Id.3.2, cf. Pl.Grg.472b ; “ἐκ τῶν μεγίστων οἰ.” Eup.117.5, cf. And.1.126, Th.8.6, etc. ; “περὶ ὀλίγας οἰ. αἱ . . τραγῳδίαι συντίθενται” Arist.Po.1453a19 ; “ἡ Μακεδόνων οἰ.” Plb.2.37.7 ; “ἡ βασιλικὴ οἰ.” D.S. 18.57.