Robin's last missile may be pinched (6)
I believe the answer is:
narrow
'be pinched' is the definition.
(I've seen this before)
'robin's last missile' is the wordplay.
'last' indicates one should take the final letters.
'missile' becomes 'arrow' (arrow is a kind of missile).
The final letter of 'robin' is 'n'.
'n'+'arrow'='NARROW'
'may' acts as a link.
(Other definitions for narrow that I've seen before include "Pinched" , "Having little breadth" , "Of small width, strait" , "Strait or confined" , "Close shave" .)