Style of the Ashcan School (7)
I believe the answer is:
realism
'style of the ashcan school' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for realism that I've seen before include "Practical approach" , "Unromantic view of the world" , "The representation of things as they are" , "Practical quality" , "Actuality" .)