1. Marked by or given to doubt
   "The doubting scientist demanded more evidence before accepting the theory";
   - questioning, skeptical [N. Amer], sceptical [Brit, Cdn]

1. Consider unlikely
   "I doubt that she will accept his proposal of marriage"
    
2. Lack confidence in
   "I doubt these reports"

See also: distrustful

Type of: disbelieve, discredit, distrust, mistrust, suspect

Encyclopedia: Doubting