Lavish women like terribly expensive originals (5)
I believe the answer is:
waste
'lavish' is the definition.
(thesaurus)
'women like terribly expensive originals' is the wordplay.
'women' becomes 'w' (standard abbreviation).
'like' becomes 'as'.
'originals' indicates taking the first letters (I've seen 'original' mean this).
The first letters of 'terribly expensive' is 'te'.
'w'+'as'+'te'='WASTE'
(Other definitions for waste that I've seen before include "Uncultivated area" , "Use to no purpose" , "Blow - rubbish" , "Spend to no purpose" , "Spend thoughtlessly or use inefficiently" .)