Raise or perforate edges with string (4)
I believe the answer is:
rope
'string' is the definition.
(I have seen 'string of pearls' mean 'rope' so perhaps 'string' could also mean 'rope')
'raise or perforate edges' is the wordplay.
'raise' says the letters should be written in reverse.
'edges' says to hollow out the word (remove centre letters) (I've seen 'edges of' mean this).
'perforate' with its middle removed is 'pe'.
'or' reversed gives 'ro'.
'ro'+'pe'='ROPE'
'with' acts as a link.
(Other definitions for rope that I've seen before include "String of pearls, say" , "Noose" , "Give a man enough . . . . and he'll hang himself" , "murder weapon" , "Pore (anag.)" .)