Wastefully extravagant (8)
I believe the answer is:
prodigal
'wastefully extravagant' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for prodigal that I've seen before include "Improvident" , "reckless" , "Squandering" , "Wastefully extravagant" , "Grip load (anag.)" .)