(~s)
Frequency: The word is one of the 3000 most common words in English.
1.
You can refer to someone who sees or notices something as an ~.
A casual ~ would have taken them to be three men out for an evening stroll...
Observers say the woman pulled a knife out of the bunch of flowers and stabbed him in the neck.
= witness
N-COUNT
2.
An ~ is someone who studies current events and situations, especially in order to comment on them and predict what will happen next. (JOURNALISM)
Political ~s believe that a new cabinet may be formed shortly.
N-COUNT: oft supp N
3.
An ~ is a person who is sent to observe an important event or situation, especially in order to make sure it happens as it should, or so that they can tell other people about it.
The president suggested that a UN ~ should attend the conference.
N-COUNT: oft supp N