WHISTLE UP A WIND - To entertain false hopes, such as in trying to borrow money for a spree or run ashore. From the sailors' superstition that a wind could be raised by whistling for it; the meaning has long since been reversed, so that 'whistling up a wind' will produce nothing: 'If he thinks that I am going to take him back after what he has done to me, he is whistling up the wind.'
Cockfosters: The name may not sound particularly elegant, but its roots are surprisingly royal. The final stop heading north on the Piccadilly Line (as well as the name of the surrounding suburb), Cockfosters was once the location of Enfield Chase, a royal park home to nearly 8,000 acres and 3,000 deer – as well as to foresters, who protected the park from would-be poachers or woodcutters. The word for the chief forester? Cock forester. The word ‘cockfoster’ was first recorded in 1524, and in 1613, a house, likely the head forester’s lodge, was written down with the same name.
Scurrilous (and its much rarer relation scurrile, which has the same meaning) comes from Middle French scurrile. The Middle French word, in turn, comes from the Latin scurrilis, from scurra, which means "buffoon" or "jester." Fittingly, 18th-century lexicographer Samuel Johnson defined scurrilous as "using such language as only the licence [sic] of a buffoon could warrant." Qualities traditionally associated with buffoonery—vulgarity, irreverence, and indecorousness—are qualities often invoked by the word scurrilous. Unlike the words of a jester, however, "scurrilous" language of the present day more often intends to seriously harm or slander than to produce a few laughs.
The expression the hair of the dog, for an alcoholic drink taken to cure a hangover, is a shortening of ‘a hair of the dog that bit you’. It comes from an old belief that someone bitten by a rabid dog could be cured of rabies by taking a potion containing some of the dog's hair. The correlation suggests that, although alcohol may be to blame for the hangover (as the dog is for the attack), a smaller portion of the same will, paradoxically, act as a cure. There is, it should be added, no scientific evidence that the cure for either a hangover or rabies actually works.
I came across some rarely used words recently. One expression I particularly like is croochie-proodles. It is scottish and means discomfort due to being in a cramped position. (Unless anyone else knows better.)