Smith’s Bible Dictionary

Tyrannus

(sovereign), the name of a man in whose school or place of audience Paul taught the gospel for two years, during his sojourn at Ephesus. See (Acts 19:9) (A.D. 52,53.) The presumption is that Tyrannus himself was a Greek, and a public teacher of philosophy or rhetoric.

Smith’s Bible Dictionary, William Smith (1863). Public domain, from the CrossWire SWORD module.