What does agitator mean?
The definition of agitator
Ag”i*ta`tor, n.
Etym: [L.]

1 One who agitates; one who stirs up or excites others; as, political reformers and agitators.
2 (Eng. Hist.)
One of a body of men appointed by the army, in Cromwell’s time, to look after their interests; — called also adjutators. Clarendon.
3 An implement for shaking or mixing.