Pictorial diagram (5)
![Ross](/clue/static/ross-mug.min.png)
I believe the answer is:
graph
'pictorial diagram' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for graph that I've seen before include "Diagram showing relationships between things" , "Visual representation" , "Diagram showing the relationship between variable quantities" , "Geometrical diagram" , "Symbolic diagram" .)