Cynic (7)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">cynic</span>' is the definition.<br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for sceptic that I've seen before include "A doubting Thomas" , "He's hard to convince" , "One questioning accepted opinions" , "One inclined to question accepted opinions" , "I may doubt that" .)
(Other definitions for doubter that I've seen before include "one such as Thomas" , "One who is not sure" , "E.g. St Thomas" .)