Emphasizes someone's lack of conviction or belief in a particular thing or idea. Alice is a doubter when it comes to supernatural stories.
Pro Tip 2/3
Positive or Negative
Often seen as negative, but can be positive if it means someone is thoughtfully questioning. He's a healthy doubter, always double-checking facts before accepting them.
Pro Tip 3/3
Not Always Persistent
A doubter could eventually become convinced and change their viewpoint. She was a doubter at first, but the impressive presentation changed her mind.