1540s, "pertaining to bile, biliary," from French bilieux, from Latin biliosus "pertaining to bile," from bilis (see bile). Meaning "wrathful, peevish, ill-tempered" (as people afflicted with an excess of bile were believed to be) is attested from 1560s. This is the main modern sense in English and French; the more literal meaning being taken up by biliary. Related: Biliousness.
bilious bil·ious (bĭl'yəs)
adj.
Of, relating to, or containing bile; biliary.
Characterized by an excess secretion of bile.
Relating to, characterized by, or experiencing gastric distress caused by a disorder of the liver or gallbladder.