Aristarchus (ăr-is-tär'kus), best ruler. A Macedonian of Thessalonica who accompanied Paul upon his third missionary journey. Acts 20:4; Acts 27:2. He was nearly killed in the tumult which Demetrius excited in Ephesus, Acts 19:29, and it is said that he was finally beheaded in Rome. Paul alludes to him both as his fellow-laborer and fellow-prisoner. Colossians 4:10; Philemon 1:24.