n.
  - the capacity to gain an accurate and deep understanding of something. 
▸an understanding of this kind.
 - Psychiatry  awareness by a mentally ill person that their mental experiences are not based in external reality.
 
 
  Derivative
  
    - insightful adj.
  - insightfully adv.
 
   
  Etymology
  ME: prob. of Scand. and Low Ger. origin.