Protester : (noun) 1: a person who dissents from some established policy [syn: dissenter,
dissident, objector, contestant]
2: someone who participates in a public display of group
feeling [syn: demonstrator]
Based on WordNet 2.0
Protester : \Pro*test"er\, n.
1. One who protests; one who utters a solemn declaration.
--Shak.
2. (Law) One who protests a bill of exchange, or note.