Starting off, heaven, weirdly has smell that is temporary (10)
I believe the answer is:
evanescent
'temporary' is the definition.
(thesaurus)
'starting off heaven weirdly has smell' is the wordplay.
'starting off' means to remove the first letter (the starting letter is removed).
'weirdly' is an anagram indicator.
'has' is a charade indicator (letters next to each other).
'smell' becomes 'scent' (synonyms).
'heaven' with its first letter taken away is 'eaven'.
'eaven' is an anagram of 'evane'.
'evane'+'scent'='EVANESCENT'
'that is' acts as a link.
(Other definitions for evanescent that I've seen before include "Passing" , "not permanent" , "Disappearing" , "Transient" , "Fast-fading" .)