Believer died twice in bus hit badly (8)
I believe the answer is:
buddhist
'believer' is the definition.
(believer in Buddhism)
'died twice in bus hit badly' is the wordplay.
'died' becomes 'd' (abbreviation next to the year of someone's death).
'twice' indicates the doubling of some letters.
'in' indicates putting letters inside.
'badly' indicates anagramming the letters.
'd' duplicated is 'dd'.
'bus'+'hit'='bushit'
'bushit' is an anagram of 'buhist'.
'dd' going inside 'buhist' is 'BUDDHIST'.
(Other definitions for buddhist that I've seen before include "Religious type" , "Dalai Lama perhaps" , "Follower of Siddartha Gautama" .)