LIVER, n. A large red organ thoughtfully provided by nature to be bilious with. The sentiments and emotions which every literary anatomist now knows to haunt the heart were anciently believed to infest the liver; and even Gascoygne, speaking of the emotional side of human nature, calls it "our hepaticall parte." It was at one time considered the seat of life; hence its name -- liver, the thing we live with. The liver is heaven's best gift to the goose; without it that bird would be unable to supply us with the Strasbourg pate.
2008 Update: A larval die-er.