chicken

Concise Oxford English Dictionary © 2008 Oxford University Press:
chicken/ˈtʃɪkɪn/

▶noun

• 1 a domestic fowl kept for its eggs or meat, especially a young one.

• 2 informal a coward.

  ■ a game in which the first person to lose their nerve and withdraw from a dangerous situation is the loser.

▶adjective informal cowardly. ▶verb (chicken out) informal be too scared to do something.

– phrases
chicken-and-egg denoting a situation in which each of two things appears to be necessary to the other. [from the question ‘Which came first, the chicken or the egg?’.]
like a headless chicken informal in a panic-stricken and unthinking manner.

– origin OE cīcen, cȳcen, of Gmc origin; prob. rel. to cock1.