Singe broken arch (4)
I believe the answer is:
char
'singe' is the definition.
(thesaurus)
'broken arch' is the wordplay.
'broken' indicates anagramming the letters.
'arch' with letters rearranged gives 'CHAR'.
(Other definitions for char that I've seen before include "Overcook - fish - daily" , "Noiseless" , "Burn lightly" , "Kind of small trout - burn it black" , "'Mrs Mopp'" .)