Easton's Bible Dictionary: M. G. Easton, M.A., D.D.

Martyr

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. The Greek word so rendered in all other cases is translated "witness."

1. In a court of justice (Mt. 18:16, 26:65; Acts 6:13, 7:58; Heb. 10:28; 1 Tim. 5:19).
2. As of one bearing testimony to the truth of what he has seen or known (Lk. 24:48; Acts 1:8, 22; Rom. 1:9; 1 Th. 2:5, 10; 1 Jn. 1:2).