evidential /-denˈshəl/ or evidenˈtiary adjective

1. Providing evidence
2. Tending to prove

evidentialˈity noun

evidenˈtially adverb

evˈidently adverb

1. Visibly (Bible)
2. Obviously
3. Manifestly
4. Apparently

in evidence

1. Received by the court as competent testimony
2. Plainly visible, conspicuous or present (adopted from the Fr en évidence)

turn Queen's or King's evidence or (US) turn State's evidence

To give evidence for the prosecution against an accomplice in a crime