Genuine Jedi fan obsesses somewhat in retirement (4,4)
I believe the answer is:
bona fide
'genuine' is the definition.
(similar in meaning)
'jedi fan obsesses somewhat in retirement' is the wordplay.
'somewhat' indicates a hidden word.
'in retirement' says the letters should be written in reverse (retire can mean to go back or backwards).
'edifanob' can be found hidden inside 'jedi fan obsesses'.
'edifanob' backwards is 'BONA FIDE'.
(Other definitions for bona fide that I've seen before include "Genuine, without fraud - in Latin" , "Genuine or in good faith" , "it's on the level" , "honest - with 12a" , "(Proof of being) genuine" .)