Rush round place in unrestrained bout of extravagance (7)
I believe the answer is:
splurge
'unrestrained bout of extravagance' is the definition.
'rush round place' is the wordplay.
'rush' becomes 'surge' ('surge' can be a synonym of 'rush').
'round' means one lot of letters goes inside another.
'place' becomes 'pl' (I've seen this in other clues).
'surge' going around 'pl' is 'SPLURGE'.
'in' acts as a link.
(Other definitions for splurge that I've seen before include "Spend money freely, be extravagant" , "Spend a lot" , "Squander" , "Binge, fling" , "Splash out" .)