Noun
1. someone who sees an event and reports what happened
2. a close observer; someone who looks at something (such as an exhibition of some kind);
"the spectators applauded the performance""television viewers""sky watchers discovered a new star"3. testimony by word or deed to your religious faith
4. (law) a person who attests to the genuineness of a document or signature by adding their own signature
5. (law) a person who testifies under oath in a court of law