Blue material one ripped from behind roughly (7)
I believe the answer is:
erotica
'blue material' is the definition.
(blue can mean pornographic)
'one ripped from behind roughly' is the wordplay.
'one' becomes 'i' (Roman numeral).
'ripped' becomes 'tore' (I've seen this before).
'from behind' says the letters should be written in reverse.
'roughly' becomes 'ca' (abbreviation for circa).
'i'+'tore'='itore'
'itore' in reverse letter order is 'eroti'.
'eroti'+'ca'='EROTICA'
(Other definitions for erotica that I've seen before include "Objects designed to arouse sexual desire" , "Salacious" , "(Items of) titillating art" , "Blue material" , "writings about sex" .)