|Easton's Bible Dictionary|
One who bears witness of the truth, and suffers death in the cause of Christ (Acts 22:20; Revelation 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 (Matthew 18:16; 26:65; Acts 6:13; 7:58; Hebrews 10:28; 1 Timothy 5:19).
(2.) As of one bearing testimony to the truth of what he has seen or known (Luke 24:48; Acts 1:8, 22; Romans 1:9; 1 Thessalonians 2:5, 10; 1 John 1:2).
Noah Webster's Dictionary
1. (n.) One who, by his death, bears witness to the truth of the gospel; one who is put to death for his religion; as, Stephen was the first Christian martyr.
2. (n.) Hence, one who sacrifices his life, his station, or what is of great value to him, for the sake of principle, or to sustain a cause.
3. (v. t.) To put to death for adhering to some belief, esp. Christianity; to sacrifice on account of faith or profession.
4. (v. t.) To persecute; to torment; to torture.
Int. Standard Bible Encyclopedia
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 Acts 22:20, "thy martyr Stephen"; and Revelation 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.
Martyr (2 Occurrences)
Acts 22:20 And when the blood of thy martyr Stephen was shed, I also was standing by, and consenting unto his death, and kept the raiment of them that slew him. (KJV WBS NIV)
Revelation 2:13 I know thy works, and where thou dwellest, even where Satan's seat is: and thou holdest fast my name, and hast not denied my faith, even in those days wherein Antipas was my faithful martyr, who was slain among you, where Satan dwelleth. (KJV WBS)