What is the meaning of Witness?

Attestation of a fact or event; testimony.

One who sees or has personal knowledge of something.

Someone called to give evidence in a court.

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

Something that serves as evidence; a sign or token.

A particular version of a text (seen as providing testimony of archetype or other earlier version)

An additional database server instance used in failover scenarios to decide whether the mirror should take over.

To furnish proof of, to show.

To take as evidence.

To see or gain knowledge of through experience.

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

To see the execution of (a legal instrument), and subscribe it for the purpose of establishing its authenticity.

Source: wiktionary.org