Definition of witnesses:
(n) :
(countable) One who sees or has personal knowledge of something.
(n) :
(countable, law) Someone called to give evidence in a court.
(n) :
(countable) One who is called upon to witness an event or action, such as a wedding or the signing of a document.
(n) :
(uncountable) Attestation of a fact or event; testimony.
(n) :
(countable) Something that serves as evidence; a sign or token.
(v) :
(transitive) To furnish proof of, to show.