USA, 1905—a situation that is likely to lead to disaster or misfortune, especially because of negligence or neglect; someone who behaves in a way that is likely to cause trouble
USA, 1976—the outcome of a situation cannot be assumed—may allude to the stereotype of a large female soprano singing the final aria of an opera—from ‘church ain’t out ’till the fat lady sings’ (1976), itself from ‘church ain’t out until the singing is over’ (1872)
USA, 1872—the first clause refers to accurate calculations, the second punningly refers to the manipulation of those calculations—based on the figure called chiasmus, i.e., in which the order of words in the first clause is inverted in the second
a representation of the letter A in scarlet cloth which Hester Prynne is condemned to wear in The Scarlet Letter (1850), by Nathaniel Hawthorne—soon came to be used figuratively in the sense of a stigma, a mark of infamy
the name of a decree issued in Nazi Germany in December 1941, under which individuals suspected of resistance or other underground activities were arrested and deported suddenly and without trace, frequently during the night—by extension: any situation, event, etc., characterised by mystery, obscurity or secrecy
Australia, 1909—to the greatest possible extent; sated with food—dolls used to have modelled wax heads with a neck shaped so that it could be sewn to a stuffed rag body
Australia, 1888—defined by Wilkes in A Dictionary of Australian Colloquialisms (1990) as “An imaginary rich uncle overseas, backing some venture in which the unwary may be persuaded to invest.”