incredulous

adjective3

1. •
   Skeptical, disbelieving, or unable to believe.

   • Xodar listened in incredulous astonishment to my narration of the events which had transpired within the arena at the rites of Issus. — 1913
2. •
   Expressing or indicative of incredulity.

   • Reactions at Sun's campus, an hour's drive from San Francisco, ranged from the fearful to the incredulous. — 2009
3. •
   (nonstandard) Difficult to believe; incredible.

   • Why euery thing adheres togither, that no dramme of a scruple, no scruple of a scruple, no obstacle, no incredulous or vnsafe circumstance […]. — 1601