witness
nounUK /ˈwɪtnəs/
US /ˈwɪtnəs/
A person who sees something happen.
The witness told the police what she saw.
OTHER MEANINGS
2. To see something happen with your own eyes.
We witnessed a beautiful sunset at the beach.
3. A person who tells a court what they saw.
He was called as a witness in the trial.
4. To sign a paper to show that it is real.
Two friends came to witness the signing of the contract.