Definition of "diagram"

noun:
- A plan, drawing, sketch or outline to show how something works, or show the relationships between the parts of a whole.
  
  from Wiktionary, Creative Commons Attribution/Share-Alike License
- A graph or chart.
  
  from Wiktionary, Creative Commons Attribution/Share-Alike License
- A functor from an index category to another category. The objects and morphisms of the index category need not have any internal substance, but rather merely outline the connective structure of at least some part of the diagram's codomain. If the index category is J and the codomain is C, then the diagram is said to be "of type J in C".
  
  from Wiktionary, Creative Commons Attribution/Share-Alike License
verb:
- To represent or indicate something using a diagram.
  
  from Wiktionary, Creative Commons Attribution/Share-Alike License