Street on fire -- terrible conflict (6)
I believe the answer is:
strife
'conflict' is the definition.
(I've seen this before)
'street on fire terrible' is the wordplay.
'street' becomes 'st' (**).
'on' indicates putting letters inside.
'terrible' indicates anagramming the letters.
'fire' is an anagram of 'rife'.
'st' placed inside 'rife' is 'STRIFE'.
(Other definitions for strife that I've seen before include "Trouble and conflict" , "Refits (anag)" , "Conflict, dispute" , "Heated discord" , "A Cockney's wife is his trouble and .....(60" .)