Learn English – “My pigs are killing me!”

Chambers Slang Dictionary dates it to the 1920s, and also records the variants hard titty, tough tiddy, tough tit, tough titties and tough tits. It is defined as ‘bad luck’ and shown to produce tough tits, toots, described, accurately enough, I would imagine, as ‘a phrase of dismissal’. A hardened nipple is, presumably, less likely to deliver the sustenance, or any other comfort, normally expected of it and so those, infants or others, who encounter such an anatomical feature might be thought unfortunate.

The Oxford English Dictionary's definition 5h of machine is ‘originally and chiefly U.S. A motor vehicle, especially a car.’ The first recorded use with this meaning is from 1901: ‘His assistant crouching at his feet out of range of the swift-flying currents of air produced by the mad flight of the machine.’ There is also a Hammett citation from 1929. The word seems to have been used in this sense throughout the first half of the twentieth century.

Machine is a versatile word. Remember the film 'Those Magnificent Men In Their Flying Machines'? And when Windows is doing some housekeeping on my computer, I am told ‘Please do not power off or unplug your machine.’