An unintelligent, but tasty, flightless bird known for having the ability to run around for a while without its head. To find some good examples of chicken go to one of these establishments:

Grocery store

See Tem42's chickens writeup for more information on this bird.

Chicken is also a dangerous game involving two cars. The two cars drive straight toward each other. Whichever car steers out of the way first loses! If neither car veers from the path, both drivers lose because their cars and bodies get all wrecked up. Exciting!

Some kids also play this game with a train. The kid stands on railroad tracks facing an oncoming train. A train can't change its path, so it's up to the kid to jump out of the way. The kid loses if he gets hit by the train or if he jumps out of the way too early for his peers' liking.

A bad guy from the Game Boy game Super Mario Land. It's a helmet-wearing war bird that flies suddenly towards Mario when it gets near his Sky Pop. It's playing chicken with Mario.

Chicken is also slang for a coward. If someone is too scared to do something like, for instance, play chicken, then his peers may call him a chicken. Oftentimes these peers will continue to chant and sing and announce that the coward is a chicken (and even throw in some chicken sounds) until the coward changes his mind and performs the dangerous deed.

People who like to lift up their shirts and show you their pot belly are showing you their chicken. It's a bashful chicken. It always seems to be turned around.