A common name designating one or more men associated with Paul. 1 City treasurer (superintendent of public works?), probably of Corinth, among Paul’s “fellow workers” sending greetings (Rom 16:23). 2 Paul’s colleague sent with Timothy from Ephesus into Macedonia (Acts 19:22). 3 An associate who remained in Corinth (2Tim 4:20).
Rom 16:23
23Gaius, who is host to me and to the whole church, greets you. Erastus, the city treasurer, and our brother Quartus, greet you.
Acts 19:22
22So he sent two of his helpers, Timothy and Erastus, to Macedonia, while he himself stayed for some time longer in Asia.
2Tim 4:20
20Erastus remained in Corinth; Trophimus I left ill in Miletus.