- sanguine
- 1319, "type of red cloth," from O.Fr. sanguin (fem. sanguine), from L. sanguineus "of blood," also "bloody, bloodthirsty," from sanguis (gen. sanguinis) "blood" (see sanguinary). Meaning "blood-red" is recorded from 1382. Meaning "cheerful, hopeful, confident" first attested 1509, since these qualities were thought in medieval physiology to spring from an excess of blood as one of the four humors.