1. Denying or questioning the tenets of especially a religion
   "a skeptical approach to the nature of miracles"
   - disbelieving, sceptical [Brit, Cdn], unbelieving 
2. Marked by or given to doubt
   "a skeptical attitude"; "a skeptical listener"
   - doubting, questioning, sceptical [Brit, Cdn]

See also: distrustful, incredulous, skeptic [N. Amer], skepticism [N. Amer]

Encyclopedia: Skeptical

• existent
• existential
• existential operator
• existential philosopher
• existential philosophy
• existential quantifier
• existentialism
• existentialist
• existentialist philosopher
• existentialist philosophy
• existing
• exit
• exit poll
• exit ramp
• Exmoor
• exobiology
• exocarp
• exocentric
• Exocet
• Exocoetidae
• exocrine
• exocrine gland
• Exocycloida
• exode
• exoderm