Besom (5)
I believe the answer is:
broom
'besom' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for broom that I've seen before include "Flowering shrub" , "Yellow-flowering shrub" , "Long-handled brush" , "Shrub or sweeping brush" , "Shrub and cleaning implement" .)