The most common and most likely answer to this crossword clue is the 6 letter word PECKER
I've seen this crossword clue in The Guardian
P
E
C
K
E
R
More clues leading to the result PECKER
Buddy explains!

The straight part
We know that "Cock/ hen" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case cock/ hen = pecker.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 PECKER mean?
PECKER noun- Someone who or something that pecks, striking or piercing in the manner of a bird's beak or bill, particularly:
- (by extension of the sense ‘beak’) A nose.
- (by extension, from the expression ‘keep one's pecker up’) Spirits, nerve, courage.
- (chiefly in the plural) Short for peckerwood ("whitey; white trash")
- (chiefly in the plural) Short for peckerhead ("dickhead; an aggressive or objectionable idiot").
- A dickhead: an unpleasant, stupid or mean person.
- An electric motor's terminal connection or wiring box.