Cynical means contemptuously distrustful of someone’s motives.
- “Those cynical men who say that democracy cannot be honest and efficient.”—FDR
Sarcastic means using bitter or caustic language against someone.
- The sarcastic clerk cost the store many customers.
Skeptical means doubting, questioning, or mistrustful.
- Candy seemed skeptical when I told her I am seeing a psychic.