Hoping to include fastener (3)
I believe the answer is:
pin
'fastener' is the definition.
(pin is a kind of fastener)
'hoping to include' is the wordplay.
'to include' says the answer is hidden in the clue.
'PIN' is hidden within 'hoping'.
(Other definitions for pin that I've seen before include "Flagged stick placed in golf hole" , "Initially, confidential number for use of bank card" , "Badge" , "Needle" , "Fastener; brooch" .)