n. One who or that which provokes, excites, promotes, or stirs up; one who stirs up anger or other passion.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
n. someone who deliberately foments trouble
Word Usage
"Recently, for example, I have become convinced of the usefulness of poetry recitation as a provoker of fluency (another time, OK?), and that certainly includes some speaking-all-together."