Enthuse to new flyer (5)
I believe the answer is:
raven
'flyer' is the definition.
(I know that raven is a flyer)
'enthuse to new' is the wordplay.
'enthuse' becomes 'rave' (I've seen this in another clue).
'to new' becomes 'n' (common abbreviation eg NT for New Testament).
'rave'+'n'='RAVEN'
(Other definitions for raven that I've seen before include "Tower of London bird" , "Flighty type" , "Species of crow" , "flesh-eating bird" , "Flyer" .)