Caput medusae, meaning "Medusa's head" in Latin, is a clinical sign characterized by the appearance of enlarged and engorged superficial epigastric veins radiating from the navel (umbilicus) across the abdomen. It's a sign of portal hypertension, a condition where blood pressure in the portal vein, which carries blood from the digestive organs to the liver, becomes abnormally high. The veins appear like snakes radiating from a central point, hence the name.