Part of a wood joint (5)
I believe the answer is:
tenon
'part of a wood joint' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for tenon that I've seen before include "Part of woodworking joint" , "piece of carpentry?" , "Mortise filler" , "Shaped end of piece of wood for slotting into a hole." , "Kind of saw" .)