Loveliness (6)
I believe the answer is:
beauty
'loveliness' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for beauty that I've seen before include "Supremely pleasing quality" , "'She walks in . . . . . ., like the night' (Byron)" , "Aesthetically pleasing quality" , "A quality pleasing to the senses" , "Period when power supply is unavailable" .)