I'm back to anger apparition (6)
I believe the answer is:
mirage
'apparition' is the definition.
(thesaurus)
'i'm back to anger' is the wordplay.
'back' is a reversal indicator.
'to anger' becomes 'rage' (rage is a kind of anger).
'im' written backwards gives 'mi'.
'mi'+'rage'='MIRAGE'
(Other definitions for mirage that I've seen before include "Something illusory and unattainable" , "Optical illusion, in a desert say" , "You might see this in desert" , "image, not what it seems" , "See it to believe it?" .)