What a graph may show (5)
I believe the answer is:
trend
'what a graph may show' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for trend that I've seen before include "Popular current taste" , "Fashion; general drift" , "General line of orientation" , "Style, vogue" , "Med. port, taken by Crusaders" .)