USA, 1911—‘to be decent’: ‘to be sufficiently clothed to see visitors’; often as a coy or jocular enquiry ‘are you decent?’—originated in the question asked when knocking at the door of an actor’s or actress’s dressing room in a theatre
first recorded in the United Kingdom in 1914, with reference to the civilizational implication of the German invasion of Belgium at the beginning of World War One; therefore, not first used by Orson Welles in Citizen Kane (1941)
‘double Dutch’, 19th century—from ‘Dutch’ in the sense of a language that few people can speak, and ‘double’ as a mere intensifier—‘High Dutch’, 17th century—loan translation from French ‘haut allemand’ (= ‘High German’), used in the sense of gibberish
USA—‘to go Dutch’ (1907): to have every participant pay their own expenses, or share expenses equally—via ‘to go Dutch treat’ (1887), from ‘Dutch treat’ (1873): a meal, etc., at which each participant pays their share of the expenses—from a German practice
UK, 1797—strength or confidence gained from drinking alcohol—alludes to the drinking habits ascribed to the Dutch—one of the phrases in which ‘Dutch’ is used derogatorily, largely because of the enmity between the English and the Dutch in the 17th and 18th centuries
UK, 1967—chiefly British—‘bums on seats’: the members of an audience, at a theatre, cinema or other place of entertainment, especially when viewed as a source of income
USA, 1946—‘to have, or to get, egg on one’s face’: to be, or to get, embarrassed or humiliated by the turn of events—refers either to having eggs thrown at one’s face or to yolk stains left on the face after the careless eating of a soft-boiled egg
U.S., second half 19th century—from the story (1850) of a man who, having declared that he could eat anything, was challenged to eat crow; the crow he had to eat was seasoned with snuff, so that the man gave up after one bite, saying “I can eat crow, but I’ll be darned if I hanker after it.”
USA, 1939—‘there is’, or ‘ain’t’, ‘no such thing as a free lunch’: everything inevitably involves a cost of some kind—literal meaning of ‘free lunch’ (first half of the 19th century): a lunch provided free of charge in a bar, saloon, etc., as a means of attracting customers
from classical Latin ‘urbī’, dative of ‘urbs’ (city), and ‘orbī’, dative of ‘orbis’ (orb, circle)—in classical Latin, ‘orbis terrarum’, ‘orbis terrae’, the orb, or circle, of the earth, meant by extension the world, since the ancients regarded the earth as a circular plane or disk