Mid 16th century; earliest use found in John Heywood (c1496–c1578), playwright and epigrammatist. From white + livered, perhaps ultimately after ancient Greek or Hellenistic Greek λευκηπατίας or λευχηπατίας cowardly, literally ‘white-livered’, reflecting the former popular belief that a light-coloured liver was considered deficient in bile or choler, and hence lacking in vigour, spirit, or courage.