So singled out for piety (9)
I believe the answer is:
godliness
'piety' is the definition.
(godliness is a kind of piety)
'so singled out' is the wordplay.
'out' indicates anagramming the letters (out can mean wrong or inaccurate).
'so'+'singled'='sosingled'
'sosingled' is an anagram of 'GODLINESS'.
'for' acts as a link.
(Other definitions for godliness that I've seen before include "reputedly close to being clean" , "A virtue" , "'Cleanliness is akin to . . . . . . . . .'" , "Respectful behaviour" , "Piety" .)