Synonyms: initiator, instigator
Definition: a person who initiates a course of action
Similar words: leader
Definition: a person who rules or guides or inspires others
Synonyms: instigant, instigator, inciter, firebrand, provoker
Definition: someone who deliberately foments trouble
Usage: she was the instigator of their quarrel
Similar words: trouble maker, troublemaker, troubler, bad hat, mischief-maker
Definition: someone who deliberately stirs up trouble