Doubter
The Century Dictionary and Cyclopedia
noun.
One who doubts; one whose opinion is unsettled or whose mind is not convinced.
the GNU version of the Collaborative International Dictionary of English
noun.
One who doubts; one whose opinion is unsettled; one who scruples.
Wiktionary, Creative Commons Attribution/Share-Alike License
noun.
One who
doubts
.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
noun.
someone who is doubtful or noncommittal about something
noun.
someone who habitually doubts accepted beliefs