No truce arranged? Slaughter (7)
I believe the answer is:
trounce
'slaughter' is the definition.
(I've seen this before)
'no truce arranged?' is the wordplay.
'arranged?' is an anagram indicator.
'no'+'truce'='notruce'
'notruce' with letters rearranged gives 'TROUNCE'.
(Other definitions for trounce that I've seen before include "Clobber" , "Rout" , "Wipe the floor with" , "Wallop" , "Thrash" .)