Smith’s Bible Dictionary
“Onesimus” means profitable, useful
Onesimus: the name of the servant or slave in whose behalf Paul wrote the Epistle to Philemon. He was a native, or certainly an inhabitant, of Colosse. (Colossians 4:9) (A.D. 58.) He fled from his master end escaped to Rome, where he was led to embrace the gospel through Paul's instrumentality. After his conversion the most happy and friendly relations sprung up between the teacher and disciple. Whether Paul desired his presence as a personal attendant or as a minister of the gospel is not certain from verse 13 of the epistle.