Gushing review (4)
I believe the answer is:
rave
'gushing review' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for rave that I've seen before include "Enthuse; rant" , "Enthusiastically favourable review" , "Talk wildly and angrily" , "Fume" , "Wild party; go mad" .)