"Relating to or denoting a stocky physique with a rounded body and head, thickset trunk, and a tendency to fat", 1920s: from Greek puknos 'thick' + -ic. The word was first used by the German psychiatrist, Ernst Kretschmer (1888–1964), in his tripartite classification of human types (the other two being asthenic and athletic).[pyknic etymology, pyknic origin, 英语词源]