The most common and most likely answer to this crossword clue is the 6 letter word TRENCH
I've seen this crossword clue in The Times
T
R
E
N
C
H
More clues leading to the result TRENCH
- Fish seen around river channel
- Run into fish in Channel
- Ditch fish in river? On the contrary
- Cut right into fish
- Ditch fashion mostly followed by church
- Ditch fish in river? The opposite
- Fish circling river’s deep depression
- Ditch fish maintaining resistance
- Ditch swimmer crossing river
- Channel swimmer crossing river
Buddy explains!

The straight part
We know that "channel" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case channel = trench.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does TRENCH mean?
TRENCH noun- A long, narrow ditch or hole dug in the ground.
- A narrow excavation as used in warfare, as a cover for besieging or emplaced forces.
- A pit, usually rectangular with smooth walls and floor, excavated during an archaeological investigation.
- A trench coat.
- (usually followed by upon) To invade, especially with regard to the rights or the exclusive authority of another; to encroach.
- (infantry) To excavate an elongated pit for protection of soldiers and or equipment, usually perpendicular to the line of sight toward the enemy.
- To excavate an elongated and often narrow pit.
- To have direction; to aim or tend.
- To cut; to form or shape by cutting; to make by incision, hewing, etc.
- To cut furrows or ditches in.
- To dig or cultivate very deeply, usually by digging parallel contiguous trenches in succession, filling each from the next.