Pursued, we hear, but morally pure (6)
I believe the answer is:
chaste
'morally pure' is the definition.
(I've seen this before)
'pursued we hear' is the wordplay.
'pursued' becomes 'chased' ('chased' can be a synonym of 'pursued').
'we hear' indicates a 'sounds like' (homophone) clue.
'chased' is a homophone of 'CHASTE'.
'but' is the link.
(Other definitions for chaste that I've seen before include "not spotted at all" , "Sexually virtuous" , "Unsullied" , "Everlasting" , "Restrained, modest" .)