Here’s What ‘Influenza’ Originally Meant

Most style guides recommend against putting an apostrophe in front of “flu”, even though it’s a shortened word. Now, the University of Oxford’s guide says, the contraction is accepted “in its own right”.

After all, the word has been clipped from its original form (influenza) since the mid-1900s, decades after its origin. It’s gone by “the flu” since at least 1839 (spelled “the Flue” at first), a century or so after it entered the English lexicon, says Merriam-Webster.

But its first definition had less to do with sniffles and tissues than you might think.

According to an etymology of the word published in Emerging Infectious Diseases, “influenza” originally had to do with the stars.

It comes from the Latin influentia, meaning “to flow into” or to influence.

“In medieval times, [an] intangible fluid given off by stars was believed to affect humans,” the journal entry reads.

“The Italian influenza referred to any disease outbreak thought to be influenced by stars.”

That meant that various diseases originally went by the name – it didn’t just refer to the chills-and-sore-muscles situation we call the flu nowadays.

In fact, the English word probably came from the phrase “influenza di catarro” (influenza of catarrh), which Italians used to describe a Europe-wide spread of the condition in 1743. (As it happens, accounts of what seems to be the flu were first clearly recorded in Italy and France in 1173).

Epidemics were often referred to as influenza in Medieval Italy, because it was thought that they were “influenced” by the stars.

Catarrh is the build-up of mucus and phlegm in the sinus, nose, and throat, so perhaps it’s no wonder it came to mean what we now call flu for English speakers.

In Italy, meanwhile, the word now refers to both influence and the flu.