Bamboo stem (4)
I believe the answer is:
cane
'bamboo stem' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for cane that I've seen before include "Walking stick; punish" , "Slender stem of bamboo etc" , "A stick to lean on" , "Birch" , "Eg, bamboo; punish" .)