Idiom is a fixed expression with a figurative meaning. Idioms serve to make language bright and emotional. Very often it’s better to use an idiom in common speech to illustrate a particular situation, rather than describe it through specific details.
The English language is full of weird idioms. Let’s look back through history to find the origin of a few of them.
‘To Blackmail’ means to demand money from somebody by means of immoral measures like violence, threats, or the potential to disclose private information. The idiom originated in Scotland around 1600. Scottish farmers paid the rent in silver coins. They were known as ‘white money’ and spelled like ‘mail’ or ‘male’. Additional payment, which clan chiefs extorted from the farmers using violence and threat was known as ‘blackmail’. Later, this word was adopted when around 1900 criminals started to send letters demanding money in order not to reveal personal secrets (Dalton, 2014).