Sceptic is a term used to describe someone who does not believe in something, often religious or spiritual beliefs. An ATHEIST is someone who does not believe in any gods or deities, while a DOUBTER is someone who questions the truth of something. An AGNOSTIC is someone who believes that the existence of a god or deity cannot be proven or disproved. A CYNIC is someone who believes that people are generally selfish and untrustworthy. A NONBELIEVER is someone who does not accept a particular belief or doctrine, while a DISBELIEVER is someone who does not accept the truth of something. Finally, an INFIDEL is someone who does not accept a particular religion or faith. All of these terms can be used to describe someone who is sceptical of something.