What is the difference between “rooster” vs. “cock” and “hen” vs. “chicken”?
Think of it like this...
Human>>>>>>Man or Woman>>>>>Child (boy or girl)
Chicken>>>>>Rooster or Hen>>>>>Chick (male:cockerel or female: pullet)
Cock is another term for rooster. Not hen.
This link offers a succinct explanation as well.
Since cock is American slang for male genitalia, it’s fallen out of use in America (not in England!) except when specifically referring to cock fighting. Chicken is genderless, hen is the female, rooster. cock and cockerel are male, and chick refers to the younglings (of either sex).