Thyatira (thȳ'a-tî'rah). A city of Asia Minor, on the northern border of Lydia. Dyeing was an important branch of its business from Homer's time, and the first New Testament mention of Thyatira, Acts 16:14, connects it with the purple-seller, Lydia. Three votive inscriptions have been found among its ruins purporting to have come from the guild of "The Dyers." Thyatira was the seat of one of the seven churches of Asia. Revelation 2:18-29. Its population now is estimated at from 17,000 to 20,000.