SYN.: οἶκοςG3624, which in Attic law denoted the whole estate, οἰκίαG3614, the dwelling only. In cl. poets οἶκος has also the latter sense, but not in prose, except in metaph. usage, where it signifies both property and household. The foregoing distinction is not, however, consistently maintained in late Greek; cf. MM, ii, xvii, and v. Thayer, s.v. οἰκία.
Henry George Liddell, Robert Scott, A Greek-English Lexicon
οἰκί-α, Ionic dialectοἰκίη, Cretan dialect and Locrian dialectϝοικία, “Leg.Gort.” 5.26, “Berl.Sitzb.” 1927.8 (5th c.BC),compare “IG” 14.636 (from Petelia) :—ἡ, building, house, dwelling, Herodotus Historicus 1.17, 114, etc.; ἡ οἰκία ἡ δημοσία “IG” 12.94.36; οἰκία ἱερά prev. work363.24; κατ᾽ οἰκίαν at home, Plato Philosophus “Laches” 180d; ἰδίᾳ καὶ κατ᾽ οἰκίας prev. author “Lg.” 788a ; ἔτυχεν ἐπὶ τῆς οἰ. was at home, 2nd c.AD(?): Xenophon Ephesius Scriptor Eroticus 5.4: in Comedy texts and Attic Prose much more frequently than οἶκος: sometimes opposed to οἶκος as house to set of apartments or room, τᾶν οἰκιᾶν τιμὰν κομιζέσθω τῶ οἴκω ἑκάστω δύο μνᾶς “SIG” 306.16 (Tegea, 4th c.BC),compare “PTeb.” 46.9 (compare 18) (2nd c.BC), 38.14, 15 (2nd c.BC), “PFay.” 31.11 (2nd c.AD). __2 in Attic dialect law, οἶκος was distinguished from οἰκία, the former being the property left at a person's death, his estate, the latter the dwelling-house only, as stated by Xenophon Historicus “Oeconomicus” 1.5, compare Herodotus Historicus 7.224, Julianus Imperator “Gal.fragment” 12, etc. __3 distinguished from συνοικία, as one's own apartments from those let out to lodgers, Aeschines Orator 1.124. __IIhousehold, domestic establishment, Plato Philosophus “Gorgias” 520e ; δὔ οἰκίας ᾤκει, i. e. he kept two establishments, Demosthenes Orator 39.26, compare Aristoteles Philosophus “Politica” 1265b26 ; more primitive than the πόλις, prev. work 1252b17, “EN” 1162a18, al. ; ὁ ἐπὶ τῆς οἰκίας the house-steward, “PCair.Zen.” 150.16 (3rd c.BC). __IIIthe household, i. e. inmates of the house, Plato Philosophus “Leges” 909b (pl.). __IVhouse or family from which one is descended, οἰκίης ἀγαθῆς Herodotus Historicus 1.107 ; οἰκίης οὐ φλαυροτέρης prev. work 99; οἰκίης οὐκ ἐπιφανέος prev. author 2.172; τῇ Κύρου οἰκίῃ συγγενέες prev. author 3.2, compare Plato Philosophus “Gorgias” 472b; ἐκ τῶν μεγίστων οἰ. Eupolis Comicus 117.5, compare Andocides Orator 1.126, Thucydides Historicus 8.6, etc.; περὶ ὀλίγας οἰ. αἱ.. τραγῳδίαι συντίθενται Aristoteles Philosophus “Poetica” 1453a19; ἡ Μακεδόνων οἰ. Polybius Historicus 2.37.7; ἡ βασιλικὴ οἰ. Diodorus Siculus Historicus 18.57. __V medical school, ἐξ οἰκίας Ἡροφίλου Erotianus Grammaticus “Praef.”, compare Galenus Medicus 17(2).145.