Dictionary

Attestation of a fact or event; testimony.

Example: She can bear witness, since she was there at the time.

One who sees or has personal knowledge of something.

Example: As a witness to the event, I can confirm that he really said that.

Someone called to give evidence in a court.

Example: The witness for the prosecution did not seem very credible.

One who is called upon to witness an event or action, such as a wedding or the signing of a document.

Example: The bridesmaid and best man at a wedding typically serve as the witnesses.

To furnish proof of, to show.

Example: 1667: round he throws his baleful eyes / That witness'd huge affliction and dismay — John Milton, Paradise Lost, Book 1 ll. 56-7

To take as evidence.

To see or gain knowledge of through experience.

Example: He witnessed the accident.

(construed with to or for) To present personal religious testimony; to preach at (someone) or on behalf of.