In a fury, I show spirit (6)
I believe the answer is:
wraith
'spirit' is the definition.
(I've seen this before)
'in a fury i' is the wordplay.
'in' is an insertion indicator.
'a fury' becomes 'wrath' (I've seen this before).
'wrath' enclosing 'i' is 'WRAITH'.
'show' acts as a link.
(Other definitions for wraith that I've seen before include "'Ghost, spectre (6)'" , "Making an emotional appeal" , "Presence" , "Deathly apparition" , "Apparition, phantom, spirit" .)