Baffle the remainder (5)
I believe the answer is:
stump
I believe this clue is a double definition.
'baffle' is the first definition.
(thesaurus)
'the remainder' is the second definition.
(thesaurus)
(Other definitions for stump that I've seen before include "Confound" , "What's left after cutting" , "Cricket post" , "clear out of money" , "Truncated trunk" .)