That's curious!

Granny Smith is a variety of green apples. The name was taken from the Australian gardener Maria Ann Smith, also known as Granny Smith. She was the one who first grew the apple in Sydney in the 1860s.

Beefeater

This term originated in 1610, meaning a well-fed servant. Around the year 1700 it began to be used to refer to the traditional guards at the Tower of London. The meaning is quite clear as it's a reference to a servant spoiled by his master, in contrast to a "loaf eater" (a servant that eats only bread).

Bug

The word bug is used nowadays to refer to an error or defect that prevents a computer from working correctly. It is believed that Thomas Edison was the first to use it with this meaning, but there is also a more recent story. In 1945, Grace Hopper, a computer pioneer at the Naval Warfare Centre in Dahlgreen, Virginia, found an insect inside a malfunctioning machine. She didn't invent the term, but she used it in the logbooks, stating that a bug had been found.

Hot dog

The use of this word to mean sausage comes from the XIX century. Hot referred to the temperature of the sausage, of course. And dog may have been a reference to the alleged contents of the sausage. In 1845 there were many accusations against sausage makers of using dog meat to make the sausage (which was not true). The term became popular and was often used in newspapers, making it as common as it is today.