Outcast Felix eventually shows up (5)
I believe the answer is:
exile
'outcast' is the definition.
(I've seen this before)
'felix eventually shows up' is the wordplay.
'shows' indicates the answer is hidden within the clue.
'up' says the letters should be written in reverse (in down clue: letters go upwards).
'elixe' can be found hidden inside 'felix eventually'.
'elixe' in reverse letter order is 'EXILE'.
(Other definitions for exile that I've seen before include "Deport" , "Expulsion from one's country" , "Person who now lives in another country" , "Refugee" , "Person forced from country" .)