Scrapping with girl's very big friend outside (8)
I believe the answer is:
disposal
'scrapping' is the definition.
(thesaurus)
'girl's very big friend outside' is the wordplay.
'girl's' becomes 'dis'.
'very big' becomes 'os' (abbreviation for outsize).
'friend' becomes 'pal' (pal is a kind of friend**).
'outside' means one lot of letters goes inside another.
'os' inserted inside 'pal' is 'posal'.
'dis'+'posal'='DISPOSAL'
'with' is the link.
(Other definitions for disposal that I've seen before include "Getting rid of something" , "arrangement" , "Availability for use" , "Deployment - management" , "Scrapping" .)