Longman Dictionary of Contemporary English - chicken

~1 n 1 »BIRD« a common farm bird that is kept for its meat and eggs  (He keeps chickens on his farm.)  (- see also hen, cock1 (1), rooster) 2 »MEAT« the meat from this bird eaten as food  (roast chicken | fried chicken | chicken soup) 3 »SB WHO IS NOT BRAVE« informal someone who is not at all brave; coward  (Don't be such a chicken!) 4 »GAME« a game in which children must do something dangerous to show that they are brave 5 which came first, the chicken or the egg? used to say that it is difficult or impossible to decide which of two things came first or which action is the cause and which is the effect 6 a chicken and egg situation/problem/thing etc a situation in which it is impossible to decide which part caused another and which is the effect of another 7 your chickens have come home to roost your bad or dishonest actions in the past have caused the problems that you have now  (- see also don't count your chickens before they've hatched count1 (8), spring chicken) chicken out phr v informal to decide at the last moment not to do something you said you would do because you are afraid  (chicken out of doing sth)  (I knew you'd chicken out of telling Dad you want to leave school.) ~2 adj informal not brave enough to do something  (Your brother is chicken.)