n.
 something said or done for amusement; a joke.
v.
 speak or act in a joking manner.
 
  Derivative
  
    - jesting adj. & n.
  - jestingly adv.
 
   
  Etymology
  ME (orig. ‘exploit, heroic deed’, later ‘a story of heroic deeds’): from earlier gest, from OFr. geste, from L. gesta ‘actions, exploits’.