Easton's Bible Dictionary (1897)
One who bears witness of the truth, and suffers death in the cause of Christ (Acts 22:20; Rev. 2:13; 17:6). In this sense Stephen was the first martyr. ) In a court of justice (Matt. 18:16; 26:65; Acts 6:13; 7:58; Heb. 10:28; 1 Tim. 5:19). ) As of one bearing testimony to the truth of what he has seen or known (Luke 24:48; Acts 1:8, 22; Rom. 1:9; 1 Thess. 2:5, 10; 1 John 1:2).
Hastings' Dictionary of the Bible (1898)
T. Acts 22:20; Rev 2:13; Ex 17:6. In other places the Greek word of the text is rendered with "witness," Matt 18:16; Luke 24:48, which is its original meaning. It was not until after the apostolic age that the word came to denote a witness who seals his testimony with his blood, but in the above passages we may observe it in a state of transition.