You've also probably heard that word more in the last few months than you have in your entire life put together.

But what does "quarantine" actually mean, and where does the word really come from?

Let's take a break from epidemiology to instead study the etymology of this extremely popular global buzzword, and to get to the root cause of the word "quarantine."

If you're going by the Merriam-Webster Dictionary definition of the word, the two you're probably most familiar with are "a restraint upon the activities or communications of a person or the transport of goods designed to prevent the spread of disease or pests" and "a state of enforced isolation."

But these are actually only the third and fourth definitions of the word.

The first and second are "a period of 40 days" and "a term during which a ship arriving in port and suspected of carrying contagious disease is held in isolation from the shore."

Probably not what you're expecting, right?

Well, let's turn back time and explore these more esoteric definitions.

Like a lot of English words, "quarantine" was largely plagiarized from Western Europe.

It's derived from the Latin word 'quadraginta' and the Italian word 'quaranta,' both of which mean "forty."

The actual act that the word "quarantine" refers to has been in use since long before the word ever came into prominence.

Even the Bible has references to the isolation of lepers in order to prevent the spread of leprosy.

Prior to the 14th century when the term was coined, many cultures even had designating areas for sequestering the sick.

In Venice, these were called 'lazarettos,' named after Lazarus, the man Jesus was said to have brought back from the dead, and also the Catholic patron saint of lepers.

And they were built outside of the city to keep the sick separate from the general population.

However, it was during history's deadliest pandemic, the Black Death—which killed around 200 million victims—that quarantine as a term came into use.

The Venetian-controlled port city of Ragusa, which is now Dubrovnik in modern Croatia, implemented a plague-time policy known as 'trentino.'

Under 'trentino,' trade ships arriving from plague-infested areas were to be isolated for a period of 30 days to see if the crew presented plague symptoms before letting them mix with the general population.

Criminals who broke the law also faced 30 days in isolation under 'trentino.'

This policy turned out to be quite successful, and over the next 80 years was also adopted by Pisa, Marseilles, and a number of other cities.

During the next century of development, the period of isolation was moved from 30 to 40 days, meaning the name changed from 'trentino' to 'quarantino' which was then anglicized to "quarantine."

There's a lot of speculation as to why they changed the number of days from 30 to 40.

And some suggest it could be an extra safety precaution, others posit it might be because of the religious significance of the number 40, like Christ's Biblical 40 days fasting in the desert.

But, like many aspects of history, it's equally likely the change was purely arbitrary.

The enforcement of the 'quarantino' was often fickle and inconsistent, and often made exceptions for the rich and influential who could simply buy themselves out of isolation when the poor bore the brunt of the law.

And that may have been several hundred years ago, but really, some things never change.

Thanks for watching this bite-sized episode of the Infographics Show!

Wanna hear more perilous plague facts to get you through your 'quarantino?'

Why not check out "What Made The Black Death (The Plague) So Deadly?" and "Could the Black Death (The Plague) Happen Again?”

In the meantime, stay safe, stay quarantined, and wash your hands!