Rotten temper is a phrase used to describe someone who has an angry or irritable disposition. It is often used to describe someone who is easily provoked and has a short fuse. BILE is a yellow-green fluid produced by the liver that helps with digestion and is stored in the gallbladder. It is also known to be associated with negative emotions such as anger, bitterness, and resentment. Therefore, BILE can be seen as a metaphor for a person's rotten temper.