extravagance (7)
I believe the answer is:
splurge
'extravagance' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for splurge that I've seen before include "Spend lavishly" , "Sudden burst of extravagance" , "Spend money freely, be extravagant" , "Fork out" , "Splash out" .)