Anaesthetic put into Edward, restrained (8)
I believe the answer is:
tethered
'restrained' is the definition.
(I've seen this in another clue)
'anaesthetic put into edward' is the wordplay.
'anaesthetic' becomes 'ether' (ether is a kind of anaesthetic).
'put into' means one lot of letters goes inside another.
'edward' becomes 'ted'.
'ether' inserted within 'ted' is 'TETHERED'.
(Other definitions for tethered that I've seen before include "Tied to something with a rope" , "limited movement" , "on a leash" , "Restrained with a rope" , "Tied (animals) up" .)