bilirubin

noun

bil·​i·​ru·​bin ˌbi-li-ˈrü-bən 

ˈbi-li-ˌrü-

: a reddish-yellow water-insoluble pigment C₃₃H₃₆N₄O₆ that is formed by the breakdown of heme, is excreted in a water-soluble form by liver cells into bile, and occurs in blood and urine especially in diseased states see jaundice

Examples of bilirubin in a Sentence

Recent Examples on the Web

An autopsy revealed that Abigail died from a high level of bilirubin in her brain, which the application points out would have manifested as jaundice. —Chris Spargo, People.com, 13 June 2025

They are thought to result from the digestive fluid bile being imbalanced, containing too much cholesterol or bilirubin or not enough bile salts. —Amber J. Tresca, Verywell Health, 11 June 2025

There were perturbations in levels of omega-6 fatty acid, homocysteine, total protein, bilirubin and a host of other things. —Bruce Y. Lee, Forbes.com, 27 Apr. 2025

When diagnosed, people with elevated bilirubin levels have average survival rates of 1-4 years. —Mark Gurarie, Health, 13 Dec. 2024

Word History

Etymology

Latin bilis + ruber red — more at red

First Known Use

1871, in the meaning defined above

Rhymes for bilirubin

• reuben
• rubin

Medical Definition

bilirubin

noun

bil·​i·​ru·​bin ˌbil-i-ˈrü-bən, ˈbil-i-ˌ 

: a reddish-yellow, crystalline, water-insoluble pigment C₃₃H₃₆N₄O₆ that is formed by the breakdown of heme, is excreted in a water-soluble conjugated form by liver cells into bile, and occurs in blood and urine especially in diseased states (such as cirrhosis, gallstones, and hemolytic anemia)

… they may become jaundiced, their skin tinged yellow by the release of the pigment bilirubin from their damaged liver.

—Larry Thompson, Discover