Easton's Bible Dictionary (1897)
Bringing profit, an Ephesian Christian who showed great kindness to Paul at Rome. He served him in many things, and had oft refreshed him. Paul expresses a warm interest in him and his household (2 Tim. 1:16-18; 4:19).
Smith's Bible Dictionary (1863)
(bringing profit) is named twice only in the New Testament, viz. (2 Timothy 1:16-18) and 2Tim 4:19 Paul mentions him in terms of grateful love as having a noble courage and generosity in his behalf, amid his trials as a prisoner at Rome, when others from whom he expected better things had deserted him. (2 Timothy 4:16) Probably other members of the family were also active Christians. (2 Timothy 4:19) It is evident from (2 Timothy 1:18) that Onesiphorus had his home at Ephesus.
Hastings' Dictionary of the Bible (1898) & Schaff's Bible Dictionary
ONESIPH'ORUS (profit-bringing), a primitive Christian who ministered to the wants of Paul at Ephesus, and afterward sought him out at Rome and openly sympathized with him. 2 Tim 1:16-18, 2 Tim 4:19.
Hitchcock's Bible Names (1869)
who brings profit