1. a person who doubts the truth or value of an idea or belief
Usage: British spelling; American spelling is ‘skeptic’
2. a person who questions or doubts generally accepted religious doctrines
Usage: British spelling; American spelling is ‘skeptic’

Examples

• As a sceptic, she questioned the politician’s promises.
• The scientist remained a sceptic until he saw convincing evidence.
• Many sceptics doubt the effectiveness of alternative medicine.
• He was a religious sceptic who preferred scientific explanations.
• The sceptic demanded proof before accepting the theory.
• Climate change sceptics often ignore scientific consensus.