observer

Definition of Observer in English :

a person who becomes aware (of things or events) through the senses

2. commentator, observer

an expert who observes and comments on something

WordNet Lexical Database for English. Princeton University. 2010.

Observer

noun

1.

a person or thing that observes

2.

a person who attends a conference solely to note the proceedings

3.

a person trained to identify aircraft, esp, formerly, a member of an aircrew

noun

1.

a person who observes something

; specif.,

a.

a soldier manning an observation post

b.

a person who attends an assembly, convention, etc., not as an official delegate but only to observe and report the proceedings

c.

an official, usually a member of a group, sent by a UN committee to collect and report facts on the situation in a special area

2.

a member of an aircraft crew, other than a pilot, with certain specialized duties and a special rating (aircraft observer)

n.

1. One who observes: an observer of local customs; observers of religious holidays.

2. One who is sent to observe and report on events or proceedings without directly participating in them.

3.

a. A crew member on a military aircraft who makes observations.

b. A member of an armed force who watches and reports from an observation post.