English▸ noun a person who watches or notices something:
to a casual observer, he was at peace.
▪ a person who follows events closely and comments publicly on them:
some observers expect interest rates to rise.
▪ a person posted in an official capacity to an area to monitor political or military events:
elections scrutinized by international observers.
▪ a person who attends a conference, inquiry, etc., to note the proceedings without participating in them:
he had been invited to attend the meeting as an observer.
▪ a person trained to spot and identify enemy aircraft or to reconnoitre enemy positions from the air:
the Royal Observer Corps.