In a Word: The Influence of Influenza

Senior managing editor and logophile Andy Hollandbeck reveals the sometimes surprising roots of common English words and phrases. Remember: Etymology tells us where a word comes from, but not what it means today.

As Mother Nature decides whether to transition fully into autumn or to linger in summertime just a few more weeks, we mere mortals must attend to more mundane tasks. Drug stores and pharmacies are already advertising the latest flu shot, an important poke to partake in, especially for the elderly and otherwise more susceptible among us.

Flu, of course, is short for influenza, which looks an awful lot like influence — and the similarity is no coincidence. Though the annual push for the influenza vaccine might influence us toward accepting that summer is well and truly over, that isn’t the connection. Influenza, after all, is centuries older than vaccines.

Historically, the flu often appears as a pandemic — or at least it hits widely enough that people of the time write about it. The first known flu pandemic happened in Europe in 1580, but of course the malady is years older than that, older than vaccines, antiseptics, and the widespread acceptance of germ theory. Physicians of old didn’t understand how influenza worked, whether it was some imbalance of the humors, the effects of certain odors, or — what they eventually landed on — the influence of the stars.

That belief was why the disease was called influenza, literally “influence,” in Italian. It traces back to Latin in- “in” and fluere “to flow.” (Fluere is the source of words like fluid and fluent, but not, surprisingly, flow.) This “flowing in” has long been used both in respect to actual water movement and in astrological contexts.

An outbreak of the flu that began in Rome in 1743 eventually found its way to the British Isles, and it brought the word influenza to English speakers along with it.

Don’t forget to get your flu shot!