I noticed Robin Michael, who is on this site, stated she learned to spell the word 'vacuum' as "vacumn". I was also taught the same thing in school around 40 years ago; I always scored the highest in my English class and won spelling bees back then. I seriously want to know when it was changed.

However it is possible that when I was at school I was taught the wrong spelling. Furthermore it is possible that the wrong spelling was quite widely used. So, it is not just a simple mistake, like two 'c's instead of two 'u's. (R.M)

  • 10
    It's always been "vacuum" for me, and I learned it 50-odd years ago.
    – Hot Licks
    Commented Apr 28, 2018 at 0:03
  • 2
    Google Ngrams makes me seriously doubt there was ever any spelling other than "vacuum". Commented Apr 28, 2018 at 0:05
  • 4
    Since the Latin was vacuum, neuter for empty, there seems no reason for an alternative spelling
    – Henry
    Commented Apr 28, 2018 at 0:08
  • 2
    @PeterShor According to this comment on a related question, it has been used in scientific literature as well.
    – JJJ
    Commented Apr 28, 2018 at 0:08
  • 7
    You realize, don't you, that with VERY rare exception, there no one has the power to "change" how a word is spelled. So asking "who" makes little sense.
    – tchrist
    Commented Apr 28, 2018 at 3:27

4 Answers 4


According to the Online Etymological Dictionary, vacuum entered English in the 1540s directly from Latin as the substantivized, neuter form of the adjective vacuus. The earliest use was as an abstract, non-count noun denoting the emptiness of space, later any void or empty space, for which one could use the Latin plural vacua or simply tack on an s.

Centuries later, however, some were apparently dissatisfied with such an odd occurrence of uu and tried out something that looked just as Latin, but more familiar:

Newspaper advertisement for House Cleaning Necessities, including "Vacumn Cleaner" (with one U, and an N).

A spelling vacumn, most likely in analogy to column and autumn, begins to appear in American newspapers in the latter half of the 19th century. Please note that not one usage occurs in the newspaper of a major city, but local papers from much smaller towns. I have found no dictionary, from that era or today, which accepts this spelling as an alternate.

vacumn of coin…
— Ashland (OH) Union, 2 Aug. 1864.

In a perfect vacumn, that is, in a space free from air, the most perishable article will keep indefinitely.
— Port Tobacco Times, and Charles County Advertiser (Port Tobacco MD), 17 Oct. 1873.

…produced the vacumn that caused the Mt. Carmel cyclone.
— Wheeling (WVa) Daily Register,25 June 1877.

Dr. E. E. Buck would respectfully announce to the citizens of Canton and vicinity that he will open Remedial Parlors on Lawrence Avenue … on April 19th, for the cure of all Diseases, by the famous vacumn treatment.
— The Stark County Democrat. (Canton, Ohio), 15 April 1880.

Mr. Villavaso … has charge of the vacumn pan from which superior sugars are made.
— The Weekly Thibodaux (LA) Sentinel, 10 Dec. 1892.

If these reporters were consciously or unconsciously advocating for a new spelling of the word, their entreaties fell on deaf ears. The rest of the Anglosphere, as in the centuries before them, retained the Latin spelling, even in the open compound that brought the word from the infinite void of space to more domestic settings: the vacuum cleaner.

Uses of the alternate spelling after the turn of the century inspire even less confidence:

A 1918 BS thesis from the University of Illinois:

A vacumn or inert atmosphere.
— Frank Albert Martin, The Preparation of Metallic Barium, Thesis (B.S.) University of Illinois, 1918. Typescript.

Yet another newspaper article, this time from the 50s:

Tally said that the more he travels in the Seventh District "the more convinced I am that the voters will abolish the congressional vacumn that exists in this district when they go to the polls on Saturday, May 31."
— Tabor City (NC) Tribune, 7 May 1952.

The transcribed remarks at a conference in Denver:

Who is really in charge of this outfit? There is no leadership, people are running around doing whatever in a vacumn.
— National Applied Resource Sciences Center, Bureau of Land Management, “Report of the Rangelands Conference: held April 13-17, 1998, at the Double Tree Hotel, 3203 Quebec Street in Denver, Colorado.”

And, rather surprisingly, a technical report from NASA:

The electrostatic sector of the present system is formed from a single piece of machinable insulator that has desirable vacumn properties—low outgassing and ability to hold a vacumn.
— NASA Technical Reports Server (NTRS), Machined Electrostatic Sector for Mass Spectrometer, 20 Feb. 2001.

Wherever you find the spelling vacumn, it in some ephemeral source like advertisements, newspaper articles, or other printed and digital writing that hasn’t undergone rigorous editing. To be accepted by a dictionary as an alternate, like catalog for catalogue, a spelling has to appear in enough newspapers of record, academic literature, government publications, fiction by established authors, etc., and perhaps adopted by educators and taught to others before it’s accepted. In other words, it doesn’t matter how many people on the internet spell it definately, that spelling will never be acceptable as standard.


Over the years, the word vacuum has been a challenge for people to spell. Nevertheless, the nineteenth-century dictionaries I checked consistently listed it as the only approved spelling, with no mention of acceptable variants.

To get a sense of how frequent the various possible spellings of vacuum are in newspapers of the past, I ran Elephind searches (which cover multiple newspaper databases from the United States, as well as the national newspaper archives of Australia, from 1800 to the present, though with decreasing representation after about 1930. Here is how the numbers come out.

The walls of the New Bridge are already raised nearly five feet, and are 24 feet asunder, which vacuum will be filled by a solid mound ; and the span of the Arch likewise measures 24 feet.

Philosophers never conceived the idea of so perfect a vacum as is found to exist in the minds of young women supposed to have finished their education in such establishments.

He has left a wife and eight children in nonage to mourn the loss of his valuable life, as well as many relations, and neighbors, who must sensibly realize the vaccum occasioned by his untimely existance.

Now that the election is over, and that there is a strong probability we shall enjoy a short respite from the feuds, the dissentions, and the turmoil, which the county seat business has occasioned for some time past——at least until the season arrives for getting up petitions and remonstrances——I propose occupying a portion of my leisure time in attempting to fill up the vaccuum created by this temporary cessation of hostilities between the upper, middle and lower sections of the county.

There are to be experiments with the magneto-electric exploder, as well as with a powerful electric machine and apparatus, contributed by Mr. Baker, and exhibited for convenience sake in a separate room. The vacumn tubes, which possess the peculiar property of creating auroras to order, are to be on view.

There is a vacume which must be properly filled up before the system can be brought to such a point as to prevent the importation of worthless women into this colony.

He certainly was at a loss to provide for the vacouum that would be left by the removal of the labouring population.

Richmond Vaccume Cleaner is the thing with which to pick the dirt off most everything.

From these results, it seems fairly clear that vacuum has always been the overwhelmingly preferred English spelling. Moreover, the spelling vacumn, although well represented in newspaper database results, appears to be only the fifth most common spelling of the word—assuming that the rate of false positives is roughly proportional for all the variant spellings.

(Research note: When I ran an Elephind search for the spelling vacuumn, the search engine returned 609 results, but I gave up looking for a confirmed match and dropped the spelling from consideration after the first 21 proved to be misreadings of vacuum. All other spellings returned a legitimate match within the first ten results, and most did so on the first [earliest] returned result. The worst performer other than vacuumn was vacumn, which didn't yield a true match until the ninth-earliest returned result.)


Looking at these Ngram hits for "vacumn", I see what appears to be 100-200 references over the past 2 centuries. On examination of the actual text, I see that about half these cannot be viewed for one reason or the other, and, of those which can be viewed, maybe a third are either apparent OCR errors or simply too fuzzy to distinguish. But this leaves about a third of the total that reasonably clearly uses "vacumn" for the spelling.

Of this "ugly" third, some appear to be from personal journals and the like where the surrounding text is not especially literate and where a simple misspelling out of ignorance is certainly likely. But most are in more credible circumstances. Without doing a rigorous accounting, it appears that the misspellings start around 1900 (which is about when "vacuum" became technically significant outside of physics labs), spurt up fairly suddenly, then "sag" down to a smaller number, to the point that after 1960 or so simple misspelling (or OCR error) is likely the culprit.

But between about 1900 and 1960 it appears that "vacumn" was a common spelling variant, even if not recognized by any dictionary. It is arguable that this spelling was due to the difficulty distinguishing the two in script or in fine print (look at some of the linked pages and notice how difficult this can be), vs "vacumn" having any "legitimate" origin. But, given the number of occurrences, there can be little doubt that some reasonably literate people favored the alternate spelling (which I must admit is no more nonsensical than the "correct" spelling).


The Oxford English Dictionary has vacuum as early as 1550, and no mention of any alternate spelling at all; in particular no mention of vacumn.

  • 3
    So all of these are just OCR errors???
    – Hot Licks
    Commented Apr 28, 2018 at 1:57
  • @HotLicks I have also looked at the OED, and can confirm that there is no other spelling than vacuum, in any of the senses listed, since the word's first appearance in English in the mid-sixteenth century. I can only assume that an eccentric vacumn spelling subsisted, which appears never to have come to the attention of the OED compilers. But if you send the examples you have found to them, and are able to place dates and necessary identification on them, they may well consider including some reference to them.
    – WS2
    Commented Nov 4, 2018 at 18:48
  • @HotLicks: Yes, I would take that to be the case. I suggest that "vacumn" (and other variants) is (i) illiteracy (ii) a misreading of the cursive script in which uum is mistaken for umn (iii) an OCR error (iv) a perpetuated mistake. There is a good parallel here: english.stackexchange.com/questions/106389/…
    – Greybeard
    Commented Dec 29, 2023 at 13:17

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