noun.
Someone who is undecided as to what is true and enquires after facts.
noun.
Someone who habitually doubts accepted beliefs and claims presented by others, requiring strong evidence before accepting any belief or claim.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
noun.
someone who habitually doubts accepted beliefs
Word Usage
"We might help to promote a more constructive debate, however, by being "as explicit as possible about what we are talking about when we use the term sceptic"."