Key cut out of channel (4)
I believe the answer is:
duct
'channel' is the definition.
(duct is a kind of channel)
'key cut out' is the wordplay.
'key' becomes 'd' (I've seen this in other clues).
'out' indicates an anagram (out can mean wrong or inaccurate).
'cut' is an anagram of 'uct'.
'd'+'uct'='DUCT'
'of' acts as a link.
(Other definitions for duct that I've seen before include "Air passage" , "Tube for conveing cable, liquid etc" , "Pipe for cables or air" , "Tube for cables, air, etc" , "Enclosed conduit for fluid" .)