This root form (lemma) is used in 3 different forms in the NT: οἰκείους (AMP), οἰκείων (GMP), οἰκεῖοι (NMP).
It is glossed in 2 different ways: ‘the household’, ‘household’.
OET GAL 6:10 Greek word=οἰκείους (oikeious) Morphology=AMP English gloss=‘household’ SR GNT GAL 6:10 word 17
OET EPH 2:19 Greek word=οἰκεῖοι (oikeioi) Morphology=NMP English gloss=‘the household’ SR GNT EPH 2:19 word 14
OET 1TIM 5:8 Greek word=οἰκείων (oikeiōn) Morphology=GMP English gloss=‘household’ SR GNT 1TIM 5:8 word 9