Witness
/ˈwɪtnəs/
noun
Attestation of a fact or event; testimony.
“She can bear witness, since she was there at the time.”
One who sees or has personal knowledge of something.
“As a witness to the event, I can confirm that he really said that.”
Someone called to give evidence in a court.
“The witness for the prosecution did not seem very credible.”
verb
To furnish proof of, to show.
“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.
“He witnessed the accident.”
Synonyms: certify