ALBERT JACK/SHAGGY DOGS: TO BLACKMAIL somebody is to demand money by threats, usually to expose secrets. This word originated from the Highlands of Scotland in the 1600s.
The "mail" in the blackmail is the old Scottish word for "rent", usually spelt either maill or male, which in turn evolved from the Old Norse word mal, meaning "agreement" or "contract".
In those days, tenants paid their rent in silver coins, which used to be known as "white money". In the 17th century, the chiefs of the Highland clans began a protection racket threatening farmers and traders with violence if they didn't pay to be protected from other clans.
This informal tax, or additional rent, soon became known as "black money" or "black rent", being the opposite of white rent.
Hence "blackmail" became part of the English language as a word used to describe the practice of obtaining money by threat of violence. Those unable to pay would have their stock confiscated and this would then be sold on the black market.
There is another suggestion for the origin of the expression black market. Centuries earlier, in medieval England, mercenaries and freelancers would travel the country and sell their fighting skills to the lords and noblemen who were raising armies.
They were hardened soldiers who lived rough for most of the time and, subjected to the elements and seldom polished, their armour often oxidised into a blackish colour. These men became known as Black Knights.
Sometimes, at local festivals, they would take part in jousting exhibitions and the victor would win his opponent's weapons and armour. The Black Knights usually triumphed but, rather than carry around extra sets of armour, they would sell them locally on what became known as the "black market".
Take your pick, but I feel the Scottish origin is the most likely source.
Someone who is footloose and fancy free is regarded as single and able to enjoy themselves by flitting around from one place to another without any responsibility to another person.
The "foot" is the bottom part of the sail on a boat. If this became detached from the boom, the lower half of the sail was regarded as "footloose" as it flapped around in the wind ("fancy free").
The expression has been in regular use since the 18th century to describe single people having fun (probably not at sea though).
Albert Jackis an English writer who is passionate about words, phrases and the stories behind them. His column is extracted from his book, Shaggy Dogs and Black Sheep, published by Penguin