Vacant blonde on the way will be attractive (8)
I believe the answer is:
becoming
'attractive' is the definition.
(I've seen this before)
'vacant blonde on the way' is the wordplay.
'vacant' suggests removing the centre.
'on the way' becomes 'coming' ('coming' can be a synonym of 'on the way').
'blonde' with its middle removed is 'be'.
'be'+'coming'='BECOMING'
'will be' is the link.
(Other definitions for becoming that I've seen before include "Undergoing a change" , "attractive" , "Getting" , "Appropriate" , "Turning into; suiting" .)