Mark hanging round to enjoy celebration (5,4)
I believe the answer is:
mardi gras
'celebration' is the definition.
(Mardi Gras is an example)
'mark hanging round to enjoy' is the wordplay.
'mark' becomes 'm'.
'hanging' becomes 'arras' (arras is a kind of hanging).
'round' is an insertion indicator.
'to enjoy' becomes 'dig' (to dig can mean to appreciate or 'get').
'arras' placed around 'dig' is 'ardigras'.
'm'+'ardigras'='MARDI GRAS'
(Other definitions for mardi gras that I've seen before include "Revelry celebrating Shrove Tuesday" , "Shrove Tuesday festival" , "Carnival (day)" , "Time for carnival" , "Shrove Tuesday celebration" .)