Burning with fresh zeal after a bad start (6)
I believe the answer is:
ablaze
'burning' is the definition.
(thesaurus)
'fresh zeal after a bad start' is the wordplay.
'fresh' is an anagram indicator.
'after' says to put letters next to each other.
'start' means to remove the last letter (I've seen 'starts' mean this).
'bad' with its last letter removed is 'ba'.
'zeal'+'ba'='zealba'
'zealba' with letters rearranged gives 'ABLAZE'.
'with' acts as a link.
(Other definitions for ablaze that I've seen before include "Well-lit" , "being toasted?" , "burnt" , "Bright" , "filled with anger" .)