In ancient Greece, a large, wide-mouthed vessel used for mixing wine and water in the context of the symposium. Pottery kraters were often decorated in the black-figure and red-figure techniques. Web resource here.

Euphronios-krater-750x750Euphronios.  Red-figure Krater with the Death of Sarpedon. Ca. 515 BCE. Museo Nazionale Etrusco di Villa Giulia, Rome.