Etymology Usage

What do you call a monthly anniversary?

Q: Is there a word like “anniversary” for a monthly event? Say, the second monthly whatever of the day I was hired.

A: There’s no monthly equivalent for the word “anniversary,” at least not one recognized by standard dictionaries. But for at least 200 years, people have been suggesting “mensiversary” to fill the gap.

“Anniversary,” comes from the Latin anniversarius, which means returning yearly. As the Oxford English Dictionary explains, the Latin word is composed of annus (year) plus versus (turned, or a turning) plus the suffix arius (connected with, pertaining to).

In English, the noun “anniversary” refers to the yearly occurrence of the date of a past event—say a wedding or 9-11 or the Apollo 11 landing on the moon.

So how would we refer to the third monthly occurrence of the date we got our new puppy? We’d probably call it the third monthly anniversary, logic be damned.

As for “mensiversary,” from the Latin mensis (month), it does indeed exist, barely, but not many people would recognize it as the monthly version of “anniversary.”

“Mensiversary” does show up in some Internet dictionaries—that is, in collections of words proposed and defined by Internet users—and a Google search fetches up about 13,000 hits. But it doesn’t appear in either the OED or, as far as we can tell, any standard dictionaries.

Don’t think “mensiversary” hasn’t had its chances, though. If it were going to catch on, it probably would have done so long ago.

The earliest reference we found comes from a letter written in 1805 by Sir James Mackintosh: “I always observe its mensiversary in my fancy.”

And we found other passing references to the word in books and journals from nearly every decade since then. So the word was available if lexicographers had wanted to make it “official.”

But it appears that even some of those adventurous writers who used “mensiversary” thought they were making it up.

In his book Prisoner of War: Or, Five Months Among the Yankees (1865), a Confederate rifleman named Anthony M. Keiley recorded this journal entry for July 9, 1864:

“Today is the first mensiversary of my imprisonment. Any super-fastidious reader who objects to my word-coinage, is hereby informed, that he is at perfect liberty to draw his pencil through the obnoxious polysyllable and substitute therefor any word, or form of words, that will better please him, but I hold it, nevertheless, to be a perfectly defensible creation.”

In short, “mensiversary” hasn’t quite made it into the English vocabulary. Similarly, there are a few adjectives that mean monthly, but they’re now obsolete and have been dropped from dictionaries.

One such word is “monthish,” which the Oxford English Dictionary defines as meaning “of or relating to a month; monthly.”

Two more are “mensal” and “mensual,” but they’re no longer used to mean monthly, either, probably because “monthly” does the job much better. Besides, most people would probably associate them, as well as “mensiversary,” with “menses” (menstruation), and “menstrual” cycles.

Update: A few of our readers have obliged with their own coinages for a monthly equivalent of an anniversary:  “luniversary,” “monthiversary,” and  “monthaversary.”

Here’s one comment: “For what it’s worth, we very commonly used the term ‘monthiversary’ at the life insurance company where I worked for many years.  In the administration of a policy, many transactions occur on the policy anniversary, and many occur monthly (for example, crediting interest, deducting charges).  Formally, you can refer to ‘the same date each month’ or words to that effect, but internally the common expression in the industry is ‘monthiversary.’  Just Googled the term and could see that the term is not at all rare.  It really serves a need.”

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