Australia, 1934—an inexhaustible supply of something, especially money—alludes to The Magic Pudding (1918), by Norman Lindsay, in which a pudding instantly renews itself as it is sliced or eaten into
USA, 1946—a feeling of regret experienced after making a purchase—also, in extended use: a feeling of regret experienced after voting for a particular person or programme
UK, 1958—a type of moustache in which the two ends extend downwards to the chin—refers to Emiliano Zapata, who was portrayed with a moustache of this kind by Marlon Brando in Viva Zapata! (1952)
a makeshift incendiary device for throwing by hand, consisting of a bottle filled with flammable liquid and with a piece of cloth as a fuse—Finland, 1940, in reference to Vyacheslav M. Molotov, who led the Soviet campaign against Finland
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