Sanguine means cheerfully confident that things will turn out well. Sanguine about the outcome, remain sanguine, less than sanguine.
The word comes from blood, since medieval medicine held that a person governed by blood among the four humours was cheerful and hopeful. That system is long gone and the temperament word survived it.
1adjectivesanguineCheerfully confident that things will turn out well.
“The manager remained sanguine about the team's chances despite three defeats in a row.”
sanguine is a quality.
Latin sanguineus means of blood, from the medieval theory that blood among the four humours made a person cheerful.
Proto-Indo-European
*h₁ésh₂r̥
Proto-Indo-European
*h₁sh₂-én-
Latin
sanguineus — of blood
Old French
sanguin
Middle English
sanguine
English, today
sanguine
Built from
From Middle English sanguine, from Old French sanguin, ultimately from Latin sanguineus (“of blood”), from sanguis (“blood”) (of uncertain origin, but probably from Proto-Indo-European h₁sh₂-én-, from h₁ésh₂r̥ (“blood”), with an obscure suffix such as -ǵʰō) -inus + -eus. The obsolete medical sense is in reference to the humour (blood) which ancient Hippocratic and later Galenic medicine associated with cheerfulness, optimism, confidence, liveliness, and spiritedness. a doublet of sanguineous.
Etymology from Wiktionary, CC BY-SA