Biles

Physiology. a bitter, alkaline, yellow or greenish liquid, secreted by the liver, that aids in absorption and digestion, especially of fats.
ill temper; peevishness.
Old Physiology. either of two humors associated with anger and gloominess.
Historical Examples

Vailima Letters Robert Louis Stevenson
The Struggles of Brown, Jones, and Robinson Anthony Trollope
The Cost of Kindness Jerome K. Jerome
The Works of Robert Louis Stevenson – Swanston Edition Vol. 25 (of 25) Robert Louis Stevenson
The Loyalists of Massachusetts James H. Stark
Scientific American Supplement, No. 561, October 2, 1886 Various
The Struggles of Brown, Jones, and Robinson Anthony Trollope
An Account of Timbuctoo and Housa Territories in the Interior of Africa Abd Salam Shabeeny
History of the Expedition under the Command of Captains Lewis and Clark, Vol. I. Meriwether Lewis and William Clark
The Complete Works of Josh Billings Henry W. Shaw

noun
a bitter greenish to golden brown alkaline fluid secreted by the liver and stored in the gall bladder. It is discharged during digestion into the duodenum, where it aids the emulsification and absorption of fats
irritability or peevishness
(archaic) either of two bodily humours, one of which (black bile) was thought to cause melancholy and the other (yellow bile) anger
verb
a Scot word for boil1
n.

bile
(bīl)
A bitter, alkaline, brownish-yellow or greenish-yellow fluid that is secreted by the liver, concentrated and stored in the gallbladder, and discharged into the duodenum of the small intestine. It helps in the digestion of fats and the neutralization of acids, such as the hydrochloric acid secreted by the stomach. Bile consists of salts, acids, cholesterol, lipids, pigments, and water. ◇ Bile salts help in the emulsification, digestion, and absorption of fats. ◇ Bile pigments are waste products formed by the breakdown of hemoglobin from old red blood cells.

Note: Bile is sometimes used figuratively to denote bitterness in general: “His writing was full of bile.”