adjective bil·ious \ ˈbil-yəs \

Definition of bilious

1 a biology : of or relating to a yellow or greenish fluid that is secreted by the liver and that aids especially in the emulsification and absorption of fats : of or relating to bile (see bile 1b)
b biology : marked by or suffering from liver dysfunction and especially excessive secretion of bile
  • a bilious attack
  • a bilious patient
c : appearing as if affected by a bilious disorder
  • a sickly bilious face
2 : of or indicative of a peevish ill-natured disposition
  • bilious commentary
  • her bilious humor
3 : sickeningly unpleasant
  • the bilious weather
  • with clapboards painted red and bilious yellow
  • —Sinclair Lewis





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Examples of bilious in a Sentence

  1. a bilious old dog who snaps at everyone

Recent Examples of bilious from the Web

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'bilious.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

Did You Know?

Bilious is one of several words whose origins trace to the old belief that four bodily humors (black bile, yellow bile, phlegm, and blood) control temperament. Just like phlegmatic ("of a slow and stolid phlegm-driven character"), melancholy ("experiencing dejection associated with black bile"), and sanguine ("of a cheerful, blood-based disposition"), bilious suggests a personality associated with an excess of one of the humors - in this case, yellow bile. Bilious, which first appeared in English in the mid-1500s, derives from the Middle French bilieux, which in turn traces to bilis, Latin for bile. In the past, "bile" was also called choler, which gives us choleric, a synonym of bilious.

Origin and Etymology of bilious

Middle French bilieux, from Latin biliosus, from bilis

BILIOUS Defined for English Language Learners


Definition of bilious for English Language Learners

  • : having or causing a sick feeling in the stomach : feeling or causing nausea

  • : angry or bad-tempered

  • : very unpleasant to look at

Medical Dictionary


adjective bil·ious \ ˈbil-yəs \

medical Definition of bilious

1 : of or relating to bile
2 : marked by or affected with disordered liver function and especially excessive secretion of bile



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very hard to disturb or upset

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