Groped around for fastening (4)
I believe the answer is:
rope
'for fastening' is the definition.
'groped around' is the wordplay.
'around' says the answer is hidden in the clue.
'ROPE' can be found hidden inside 'groped'.
(Other definitions for rope that I've seen before include "murder weapon" , "Stout cord" , "Strong line" , "Pore (anag.)" , "A thick strong cord" .)