The term 'ringleader' is often used to describe someone who is the leader of a group or organization. This person is usually the one who instigates or agitates the group to take action. The two crossword solutions for this term are 'AGITATOR' (8 letters) and 'INSTIGATOR' (10 letters). An AGITATOR is someone who stirs up trouble or encourages people to take action, while an INSTIGATOR is someone who initiates or starts something. Both terms can be used to describe the ringleader of a group.