Upper part of the windpipe (6)
I believe the answer is:
larynx
'upper part of the windpipe' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for larynx that I've seen before include "Location of vocal cords" , "part of neck" , "The formal voice box" , "The voice box, part of throat" , "Upper part of the windpipe" .)