Easton's Bible Dictionary (1897)
Son of Tolmai, one of the twelve apostles (Matt. 10:3; Acts 1:13); generally supposed to have been the same as Nathanael. In the synoptic gospels Philip and Bartholomew are always mentioned together, while Nathanael is never mentioned; in the fourth gospel, on the other hand, Philip and Nathanael are similarly mentioned together, but nothing is said of Bartholomew. He was one of the disciples to whom our Lord appeared at the Sea of Tiberias after his resurrection (John 21:2). He was also a witness of the Ascension (Acts 1:4, 12, 13). He was an “Israelite indeed” (John 1:47).
Smith's Bible Dictionary (1863)
(son of Tolmai), one of the twelve apostles of Christ. (Matthew 10:3; Mark 3:18; Luke 6:14; Acts 1:13) It has been not improperly conjectured that he is identical with Nathanael. (John 1:45) ff. He is said to have preached the gospel in India, that is, probably, Arabia Felix, and according to some in Armenia.
Hastings' Dictionary of the Bible (1898) & Schaff's Bible Dictionary
BARTHOL'OMEW (son of Tolmai) is supposed to be the same person who is elsewhere called Nathanael. This conjecture rests in part upon the fact that Philip and Nathanael are associated together by John, and in the parallel passages of the other evangelists Philip and Bartholomew are associated; and further, that Bartholomew is not mentioned in John's list of the twelve, nor is Nathanael in the list of the other evangelists. It is therefore in every way likely that he bore two names, as so many others did.
We know nothing of his history save the fact of his conversion, John 1:45-51, and his presence on the Lake of Tiberias when the risen Lord appeared to him and other disciples. John 21:2.
Hitchcock's Bible Names (1869)
a son that suspends the waters