What does sanguineous mean?
Sanguineous is an uncommon adjective with two connected historical senses. Its clearest modern association is with the color of blood: blood-red, crimson, or deeply red. It can also describe a person or an outlook as confident and optimistic, sometimes with the implication that the confidence is unwarranted. The word now sounds formal, literary, or archaic, especially when used for the optimistic sense, while “sanguine” is the more familiar modern choice. Sanguineous comes from a Latin family associated with blood, which explains both its color meaning and its older association with vitality, cheerfulness, and hopefulness. The word is useful in descriptive writing and historical prose, though its less familiar status may make it especially noticeable in ordinary contemporary speech.
Blood-red or deeply red.
"The room was illuminated by sanguineous light from the stained-glass windows."
Now uncommon but firmly established; it is more often encountered in literary or historical writing.
Confident or optimistic, especially to an excessive degree.
"The company remained sanguine despite the disappointing results."
More typical of formal or historical usage than of everyday contemporary speech.
Sanguineous once meant blood-red, cheerful, and optimistic; today its most vivid surviving sense is the color of blood itself.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does sanguineous come from?
Sanguineous derives from Latin sanguineus, meaning “of blood” or “blood-red,” from sanguis, “blood.” The same root also produced sanguine, sanguinary, and consanguineous. In English, the adjective developed a figurative sense of cheerful, vigorous, or optimistic, probably through associations with blood’s vitality, before settling increasingly on the literal color meaning.
Related word forms
How sanguineous is actually used
The color sense is established but uncommon. The sense meaning confident or optimistic is more typical of formal or historical writing, where it may suggest overconfidence rather than cautious optimism.
Easily confused with sanguineous
Sanguine is the more usual modern word for confident or optimistic, while sanguineous is now chiefly used for blood-red and appears in formal or archaic contexts.