The refusal or inability to eat or swallow, a term covering both voluntary rejection of food and physical incapacity. In neurology it describes the loss of feeding behavior after damage to the brain’s hunger centers, famously demonstrated in laboratory animals with hypothalamic lesions that starve amid abundant food. In clinical practice it prompts urgent evaluation: is the patient unwilling to eat, as in severe depression or eating disorders, or unable, as in stroke-related dysphagia or esophageal obstruction? The distinction determines everything about management, from psychiatric care to feeding tubes. The word’s breadth is its limitation, which is why modern medicine prefers specific diagnoses, but as a descriptive starting point it captures the stark clinical fact of a patient who does not eat.