Lucy Burroughs answered
If a chicken appears in your dream, you could interpret it as a symbol of cowardliness or lack of self-control or will-power.
What else can you remember about your dream? If the chicken seemed out of place - if it appeared in a library, for example - then you might be more inclined to believe an abstract interpretation, such as the one above. However, if you were visiting a farm in your dream, seeing a chicken would be quite normal, and wouldn't require much analyzing!
Personal Meaning
What do chickens mean to you? This idea of a personal meaning is quite an important thing to consider when you're trying to interpret your dreams; for example, a chicken would mean something entirely different to someone with a phobia of chickens to someone who grew up with them.
Chickens As Symbols Of Cowardice
There's a reason people refer to cowards as chickens sometimes - chickens do tend to be wary, jumpy creatures who will run away if you get too close. Maybe your dream is suggesting that you need to stand your ground more instead of running from your problems.