Adria in Easton's Bible Dictionary

Acts 27:27; R.V., "the sea of Adria"), the Adriatic Sea, including in Paul's time the whole of the Mediterranean lying between Crete and Sicily. It is the modern Gulf of Venice, the _Mare Superum_ of the Romans, as distinguished from the _Mare Inferum_ or Tyrrhenian Sea.

Link: https://bible-history.com/eastons/A/Adria/