Heartless girl loving to be attractive (9)
I believe the answer is:
glamorous
'attractive' is the definition.
(thesaurus)
'heartless girl loving' is the wordplay.
'heartless' suggests removing the centre.
'loving' becomes 'amorous' ('amorous' can be similar in meaning to 'loving'**).
'girl' with its centre taken out is 'gl'.
'gl'+'amorous'='GLAMOROUS'
'to be' acts as a link.
(Other definitions for glamorous that I've seen before include "in a showy way?" , "Smart; glittering" , "Alluring" , "Alluringly appealing" , "Gorgeous" .)