One who testifies to any fact from his own personal knowledge. Under the Mosaic law, two witnesses under oath were necessary to convict a person charged with a capital crime, Nu 35:30; and if the criminal was stoned, the witnesses were bound to cast the first stones, De 17:6-7Ac 7:58. The Greek word for witness isMARTYR, which see.
The apostles were witnesses, in proclaiming to the world the facts of the gospel, Ac 1:8,22 2:32 2Pe 1:12,16-18; and Christ is a "faithful witness," in testifying to men of heavenly things, Joh 3:12Re 1:5. The heroes of the ancient church are "witnesses" to the power of true faith, Heb 12:1.