curiosus

Etymology
Back-formation from by deletion of the negative prefix  in order to remain with the opposite meaning.

Adjective

 * 1) Careful, diligent, thoughtful, devoted.
 * 2) Elaborate, complicated.
 * 3) That injures himself by care; careworn, emaciated, wasted, lean.
 * 4)  Curious, inquisitive.
 * 5)  Meddlesome, officious, prying, interfering, curious, inquisitive.

Noun

 * 1) One who pries; a spy or scout; secret police, informer.