Source : Webster's Revised Unabridged Dictionary (1913)

Sceptic \Scep"tic\, Sceptical \Scep"tic*al\, Scepticism
\Scep"ti*cism\,
   etc. See {Skeptic}, {Skeptical}, {Skepticism}, etc.

Source : WordNet®

sceptical
     adj 1: marked by or given to doubt; "a skeptical attitude"; "a
            skeptical listener" [syn: {doubting}, {questioning}, {skeptical}]
     2: denying or questioning the tenets of especially a religion;
        "a skeptical approach to the nature of miracles" [syn: {disbelieving},
         {skeptical}, {unbelieving}]