Here's a breakdown:
* Dr. Guillotin proposed the use of a machine for swift and painless executions in 1789, during the French Revolution.
* The machine itself wasn't his invention. It was likely inspired by similar devices used elsewhere in Europe. However, he was a vocal advocate for its use and became associated with it.
* The machine gained the name "guillotine" in his honor.
* The word entered the English language in the late 18th century, becoming a synonym for the execution device and, later, for the method of execution itself.
So, the word "guillotine" is a direct borrowing from the name of the man who championed its use, even though he didn't actually invent it.