Wooden peg (5)
I believe the answer is:
dowel
'wooden peg' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for dowel that I've seen before include "Linking peg" , "Headless peg used for joining components" , "Short peg used as a fastener" , "Wooden pin used in carpentry" , "Peg used in joinery" .)