In a manner that shows a belief that people are motivated purely by self-interest; distrustfully. She cynically remarked that the politician's promises were just a ploy to win votes.
In a way that shows a lack of faith in the sincerity or integrity of others. He cynically assumed that the charity event was just a publicity stunt.
In a manner that is scornful of the motives or virtues of others. The journalist cynically reported on the company's supposed altruism, suggesting it was merely a tax dodge.