Duck in English Channel heading north (5)
I believe the answer is:
evade
'duck' is the definition.
(I know that duck can be written as evade)
'english channel heading north' is the wordplay.
'english' becomes 'E' (abbreviation).
'channel' becomes 'dave' (Dave is a British free-to-air television station).
'heading north' says the letters should be written in reverse (in a down clue, letters travel north).
'e'+'dave'='edave'
'edave' in reverse letter order is 'EVADE'.
'in' is the link.
(Other definitions for evade that I've seen before include "bypass" , "Hedge" , "Dodge, elude" , "Manage to avoid" , "Escape (esp. by guile)" .)