yellow bile

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun One of the four humors of ancient and medieval physiology, thought to cause anger and bad temper when present in excess; choler.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun One of the four humours of ancient and mediaeval physiology, that was believed to be secreted by the liver and to cause irascibility, anger, and bad temper when present in excess.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a humor that was once believed to be secreted by the liver and to cause irritability and anger