Excess remnant with piece in shreds (12)
I believe the answer is:
intemperance
'excess' is the definition.
(thesaurus)
'remnant with piece in shreds' is the wordplay.
'with' says to put letters next to each other.
'in shreds' is an anagram indicator.
'remnant' after 'piece' is 'pieceremnant'.
'pieceremnant' with letters rearranged gives 'INTEMPERANCE'.
(Other definitions for intemperance that I've seen before include "excess drunkenness?" , "lack of restraint" , "Unrestrained alcohol consumption" , "bingeing" .)