mar'-ter (martus, Aeolic martur): One who gives heed, and so, a "witness," so translated in numerous passages, both as of one bearing testimony, and also as of one who is a spectator of anything (see WITNESS). In the King James Version rendered "martyr" in Ac 22:20, "thy martyr Stephen"; and Re 2:13, "Antipas my faithful martyr"; also 17:6, "the blood of the martyrs of Jesus," where alone the American Standard Revised Version retains "martyrs." These 3 passages are the beginning of the use of the word "martyr" for such witnesses as were faithful even unto death, its uniform modern use.
The International Standard Bible Encyclopedia
Martyr
The International Standard Bible Encyclopedia, James Orr (1915). Public domain, from the CrossWire SWORD module.