Chickens And Roosters

"Chicken" originally referred to chicks, not the species itself. The species as a whole was then called domestic fowl, or just fowl. This use of "chicken" survives in the phrase "Hen and Chickens", sometimes used as a British public house or theatre name, and to name groups of one large and many small rocks or islands in the sea (Hen and Chicken Islands).
In the Deep South of the United States chickens are also referred to by the slang term yardbird.