Stretch, as one's neck (5)
I believe the answer is:
crane
'stretch as one's neck' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for crane that I've seen before include "Bird; dockside machine" , "Bird; mechanical lift" , "Stretch out (one's neck)" , "Bird; hoister" , "Stretch to see" .)