a. [F. sanguin, L. sanguineus, fr. sanguis blood. Cf. Sanguineous.] 1. Having the color of blood; red. “Of his complexion he was sanguine.” Chaucer. “Like to that sanguine flower inscribed with woe.” Milton.2. Characterized by abundance and active circulation of blood; as a sanguine bodily temperament. 3. Warm; ardent; as a sanguine temper. 4. Anticipating the best; not despondent; confident; full of hope; as sanguine of success. Syn. — Warm; ardent; lively; confident; hopeful.