Author Bruce Rodgers defines the term as "1. any boy under the age of consent, heterosexual, fair of face, and unfamiliar with homosexuality ("So many chickens were flapping around that I thought we were touring Colonel Sanders' plantation”) 2. juvenile, youthful, young-looking.
[2] In the subculture of the gay community which uses handkerchiefs or bandanas as a code, people who identify as "Chicken" wear a Kewpie doll in their left back pocket.
Those who are interested in young men - referred to as chickenhawks—are denoted in the hanky code as wearing one on the right.
[3] David Henry Sterry, a former prostitute turned actor and director, titled his 2002 memoir, Chicken: Self-Portrait of a Young Man for Rent.
[4] Author Philip Herbst traces its origin to the 19th century, where it was used to describe the youngest sailors on a ship, who were often used for sexual purposes.