chicken
http://grafx.dli.com/slang/images/220/chicken_220.jpg
Definition: A coward; someone who is afriad; someone who is not daring or willing to take risks
Example: 1) Don't be a chicken -- go introduce yourself to the professor
Come on, you chicken. Just try one of my homemade cookies
Etymology: Many chickens are yellow, and the color yellow has long been associated with cowardice or lack of courage
Synonyms: yellow
