illustration in WordNet English dictionary

1. an item of information that is typical of a class or group
   "this patient provides a typical example of the syndrome"; "there is an example on page 10"
   example  illustration  instance  representative 
   
2. showing by example
   exemplification  illustration 
   
3. a visual representation (a picture or diagram) that is used make some subject more pleasing or easier to understand
   illustration 
   
4. artwork that helps make something clear or attractive
   illustration