1. see smth. happen:
- We witnessed the meeting between the two great men.
2. observe an event in order to give testimony on it if required:
- Will you witness his signature on this deed?
3. give evidence of smth.; show smth.:
- Her pale face witnessed the agitation she felt.
witness to something—
1. give testimony (as in court) regarding smth.:
- He witnessed to having seen the accused near the scene of the crime.
2. prove or corroborate smth.:
- Partnerships necessitate mutual praying and planning. They also witness to the unity of the church in the world.