1) belonging to a house or family, domestic, intimate
1a) belonging to one's household, related by blood, kindred
1b) belonging to the household of God
1c) belonging, devoted to, adherents of a thing
Part of Speech: adjective
Citing in TDNT: 5:134, 674
From G3624; domestic, that is, (as noun), a relative, adherent: - (those) of the (his own) house (-hold).
These two sites give similar information, with the definition from several dictionaries and statistics on the use of the word.
Perseus Digital Library
University of Chicago's Logion lexicon
Thayer's dictionary plus other information.
From this site's dictionary (in Italian)
Click on the first column to search for that word as a form of the root οἰκεῖος; click on the second column to search for that grammatical form of the root οἰκεῖος; click on the third column to search for that word and grammatical form; click on the total to search for the root οἰκεῖος.