One that demonstrates, such as a participant in a public display of opinion.(noun)
An article or product used in a demonstration.(noun)
American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Use "demonstrator" in a sentence
"June 5th, 2009 at 1: 19 pm if you think about it the soldier driving this tank and who refused to run over the demonstrator is an hero too just like the demonstator who risked his life in an act of defiance."
"A policeman bashed his rifle into the mouth of a demonstrator from the Kanarin camp, knocking out his front teeth."
"Notice anything unusual about the second demonstrator from the right?"