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