1927 (translation of German ‘Hackordnung’): a dominance hierarchy, seen especially in domestic poultry, that is maintained by one bird pecking another of lower status—hence (1929): any hierarchy based on rank or status
UK, 1806—‘to be able to sleep at night’: to be untroubled by the moral consequences of one’s actions, or by the risks and responsibilities of one’s situation
USA, 1885—a condition of carefreeness, of ease, usually one marked by financial security—also (USA, 1889) in sporting contexts, a situation where winning will be easy
a person exercising an insidious or corrupting influence, especially over a ruler, government, etc.—UK, 1917—refers to Grigori Efimovich Rasputin (circa 1869-1916), mystic and influential favourite at the court of Tsar Nicholas II
UK, 1923—the north-east corner of Hyde Park, London, near Marble Arch, where public speaking and debate are traditionally permitted with minimal restriction—by extension: any location where public speaking and debate are permitted or encouraged
wealth gained in one generation of a family will be lost by the third generation—USA, 1874—refers to a hard-working man wearing a shirt with nothing over it