Totally baffle (5)
I believe the answer is:
stump
'totally baffle' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for stump that I've seen before include "Remnant of felled tree" , "Nonplus" , "Remains of tree - puzzle" , "Wicket part - dumbfound" , "Confound" .)