Charles Ellicott Commentary Acts 14:1

"And it came to pass in Iconium that they entered together into the synagogue of the Jews, and so spake that a great multitude both of Jews and of Greeks believed." — Acts 14:1 (ASV)

Both of the Jews and also of the Greeks.—The latter term is used in its wider sense, as in Mark 7:26 and elsewhere, as equivalent to Gentile, but it implies that those who were so described spoke and understood Greek. In the former instance these would probably be the “proselytes of the gate” who heard the Apostles in the synagogue.