Makeshift plug hole? (7)
I believe the answer is:
stopgap
'makeshift' is the definition.
(I know that makeshift can be written as stopgap)
'plug hole?' is the wordplay.
'plug' becomes 'stop' (stop can mean to plug a gap).
'hole?' becomes 'gap' (hole is a kind of gap).
'stop'+'gap'='STOPGAP'
(Other definitions for stopgap that I've seen before include "Provisional" , "Improvisation" , "caretaker" , "Temporary fix" , "A temporary substitute or solution" .)