Enthuse (4)
(Other definitions for rave that I've seen before include "Talk with extreme enthusiasm or wild delirium" , "Enthuse; rant" , "modern dance music" , "Rage" , "Talk wildly in modern youth dance" .)
'enthuse' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for gush that I've seen before include "Sudden stream or jet" , "Spout like geyser" , "Pour forth" , "Flow unceasingly" , "Talk effusively" .)