Rave (about) (7)
I believe the answer is:
enthuse
'rave about' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for enthuse that I've seen before include "Show strong approval" , "Show eagerness" , "Show feeling of eager liking and approval" , "Make (someone) interested and excited" , "Appear keenly interested" .)