What is another word for "witness"?

Roget's Thesaurus (1911) lists these synonyms for "witness": abroad, actor, administrative, adventurer, and, appeal, appellate, arbitration, ass, assize, bar, barmote, behold, beholder, bench, bidder, board, box, bungler, bunko, bureau, burghmote, bystander, capper, carpetbagger, charlatan, cheat, cloth, clothing, cockatrice, common, conjuror, council, county, court, court-baron, court-leet, crimp, deceive, deceiver.