The following phrases were chosen at random from the wealth of material:
Dogs Breakfast – a mess or muddle.
Origin: This is a 20th century phrase. Eric Partridge, in the 1937 edition of his ‘Dictionary of Slang and Unconventional English’ lists it as “a mess: low Glasgow”.
Rack your brains – to strain mentally to recall or to understand something
Origin: The rack was a mediaeval torture device. The crude but, one presumes, effective racks often tore the victim’s limbs from their bodies. It isn’t surprising that ‘rack’ was adopted as a verb meaning to cause pain and anguish. Shakespeare was one of many authors who used this. For example, from Twelfth Night, 1601:
“How haue the houres rack’d, and tortur’d me, Since I haue lost thee?”
Weasel words – Ambiguous or quibbling speech.
Origin: Stewart Chaplin’s story Stained glass political platform, 1900, contains this line:
“Why, weasel words are words that suck the life out of the words next to them, just as a weasel sucks the egg and leaves the shell.”
Thanks to Jonny of Do They Hurt for the link.