Australia, 1998—a pair of short, tight-fitting men’s swimming trunks—refers to the appearance of the male genitals in figure-hugging trunks—‘budgie’: colloquial abbreviation of ‘budgerigar’, denoting a small Australian parrot
UK, 1806—very rapidly and thoroughly—refers to a dose of aperient salts—has come to be also used in the extended form ‘like a dose of salts through + noun’
‘red rag’—a piece of red cloth used to provoke an animal—hence, figuratively, a source of provocation or annoyance, something which excites violent indignation—the notion occurs in the late 16th century
USA, 1893—the part of a town or city in which prostitution and other commercial sexual activities are concentrated—originally used of Louisville, Kentucky—from the use of a red light as a sign outside a brothel
Australia, 1887—a forlorn hope, no prospect whatever—may refer to the British convict William Buckley (1780-1856), who escaped from custody in 1803 and lived for thirty-two years with Aboriginal people
1733—denotes imaginary or non-existent people—refers to John Falstaff’s vaunting tale in the First Part of King Henry the Fourth, by William Shakespeare, in which two men in buckram suits gradually become eleven
UK, 1985—to be ‘stale’, to be no longer innovative, relevant, or effective—refers to the practice introduced in Britain in the early 1970s of stamping perishable goods with the latest date by which they may be sold
UK, 1805—personifies France or the French people, or designates a typical Frenchman—composed of ‘Johnny’, a pet form of ‘John’ used, with modifying word, to designate a person of the type, group, etc., specified, and of French ‘crapaud’ (a toad)—coined by British sailors during the Napoleonic Wars
UK, 1830—‘Jenny Darby’, ‘Johnny Darm’, and variants, were originally opprobrious names for any member of the new Metropolitan Police introduced in 1829 by Robert Peel—alterations of ‘gendarme’, with full or partial folk-etymological remodelling variously after the female forename ‘Jenny’, the male forename ‘Johnny’, and the surname ‘Darby’