Pornographic (4)
I believe the answer is:
blue
'pornographic' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for blue that I've seen before include "Varsity sportsman" , "e.g. Indigo" , "Dispirited in cerulean way" , "Unusual moon" , "Miserable - cerulean" .)