a manager put in charge of another person's household, property or funds, with real authority to act and a reckoning to face
The word joins the idea of a household (οἶκος) to the idea of parcelling things out, and it names one recognizable figure in the ancient world: the man who ran an estate day by day for the person who owned it. He was very often a slave or a freed slave, and that is the point rather than an embarrassment. He could buy, sell, lend and settle accounts in his master's name, and none of it was his. Everything he touched belonged to someone else, and one day he would be asked about it.
That single figure explains the whole range of the word:
- in the parables he is the estate manager who is trusted, or caught, or dismissed;
- in a city he is the officer who handles public money on the city's behalf;
- in the letters he is an apostle, a church leader, or any believer at all, holding something that belongs to God.
The move from the first use to the last is not a leap. The picture was ready made for anyone handed something valuable that is not his own, and the writers of the New Testament use it exactly that way. What travels with the picture every time is the pair of demands the job carried: genuine freedom to act, and a strict accounting afterwards. That is why the word keeps company with the language of being found faithful.
Notice what it does not mean. It never names the owner (οἰκοδεσπότης), and it is not simply a word for a servant who takes orders (ὑπηρέτης). A manager decides things. The work itself, as against the person doing it, has its own word (οἰκονομία), and Luke 16:3 puts the two side by side in a single sentence.
Nuances
What rank of city office the title names at Romans 16:23, and so what social standing Erastus held.
- contestedThe title corresponds to the Roman office of quaestor, a senior city magistracy, so Erastus belonged to the local elite.; J. K. Goodrich, "Erastus, Quaestor of Corinth: The Administrative Rank of ὁ οἰκονόμος τῆς πόλεως (Rom 16.23)," NTS 56 (2010): 90-115; J. K. Goodrich, Paul as an Administrator of God in 1 Corinthians, SNTSMS 152 (Cambridge, 2012)
- contestedCorinth as a Roman colony had no quaestorship, so the title names a lesser city financial officer.; A. Weiss, "Keine Quästoren in Korinth: Zu Goodrichs (und Theißens) These über das Amt des Erastos (Röm 16.23)," NTS 56 (2010): 576-581
- contestedThe title names a low ranking financial officer, most probably a public slave or a freedman.; S. J. Friesen, "The Wrong Erastus: Ideology, Archaeology, and Exegesis," in Corinth in Context: Comparative Studies on Religion and Society (Brill, 2010)