IPA: /ˈaɪˌwɪtnəs/
KK: /ˈaɪˌwɪtnəs/
A person who has seen an event or situation and can provide a description of what happened.
The eyewitness testified in court about what he saw during the accident.
Eyewitness → It is formed from "eye" (from Old English "ēage", meaning the organ of sight) and "witness" (from Old English "witan", meaning to know or to see). An eyewitness is someone who has seen an event with their own eyes and can testify to it.
Think of someone who has 'seen' something with their own 'eyes' — that's why an eyewitness is a person who directly observes an event.