Faculty for sound judgment (5)
I believe the answer is:
sense
This clue is a double definition.
'faculty' is the first definition.
(I know that sense is a type of faculty)
'sound judgment' is the second definition.
(I've seen this in another clue)
'for' is the link.
(Other definitions for sense that I've seen before include "Feel; discernment" , "Inward feeling" , "Understand" , "See 16" , "Could be common or horse" .)