Answer: dissident

AnswerCrossword Clue
DISSIDENT

Naysayer

DISSIDENT

In opposition

DISSIDENT

Not agreeing.

DISSIDENT
Nonconformist
DISSIDENT
Andrei Sakharov in the Soviet era, e.g.
DISSIDENTOne casting a "no" vote
DISSIDENTGulag internee, e.g.
DISSIDENTThorn in a dictator's side