Fish right inside the channel (6)
I believe the answer is:
trench
'the channel' is the definition.
(thesaurus)
'fish right' is the wordplay.
I cannot really see how this works, but
'right' could be 'r' (common abbreviation) and 'r' is found in the answer.
'fish' could be 'tench' (tench is a kind of fish) and 'tench' is found within the remaining letters.
This accounts for all the letters.
This explanation may well be incorrect...
'inside' acts as a link.
Can you help me to learn more?
(Other definitions for trench that I've seen before include "Military cut in the earth" , "at the front" , "Long narrow ditch" , "Ditch dug as fortification" , "Fish; move on ice" .)