Unbelieving (7)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">unbelieving</span>' is the definition.<br/ ><span class="explanation-format__explanation">(similar in meaning)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for incredulous that I've seen before include "Unwilling to believe something" , "Unable to believe something" , "Sceptical, unbelieving" .)
(Other definitions for cynical that I've seen before include "Of a pessimistic disposition about the world" , "Contemptuous, mocking" , "Disinclined to believe the sincerity of others" , "Believing the worst of motives" , "streetwise" .)