witless
adjective /ˈwɪtləs/
  /ˈwɪtləs/
 Idioms - silly or stupid; not sensible synonym foolishTopics Personal qualitiesc2Word OriginOld English witlēas ‘crazy, dazed’ (see wit, -less).
 
Idioms 
be scared/bored witless 
- (informal) to be extremely frightened or boredTopics Feelingsc2