If I want to say the first three months of the year in one word, I would say "the first quarter".
Which word should I use to refer to a period of four months?

  • 7
    What is the context where you want to use this term? Why don't you want to just say "four months" or "the first four months of the year"?
    – The Photon
    Commented May 11, 2020 at 15:18
  • 2
    Are you really looking for a single word? Please edit your question to clarify; I have assumed so (because of the title) but I agree with several others here that "four months" is a better option.
    – Glorfindel
    Commented May 11, 2020 at 20:01
  • 1
    An example of how you would use the word might help. I can't imagine the context in which you would need this (or want it--any single word is likely to fail to be understood by many readers).
    – David K
    Commented May 13, 2020 at 12:42
  • Comments are not for extended discussion; this conversation has been moved to chat. Comments should be used to improve the question, not answer it.
    – Glorfindel
    Commented May 14, 2020 at 5:48
  • elsewhere on eng.SE: english.stackexchange.com/questions/571390/…
    – Pacerier
    Commented Oct 28, 2023 at 17:35

8 Answers 8


It isn't common to speak of a four-month period, at least in the United States where I live. Thus, although others have suggested words for this, my recommendation is to not use them. Very few people would use such a word in English; the more natural way is to speak of a four-month period or some variation on that expression.

For example:

Sales were down during the four-month period ending (or beginning) in April.

  • 6
    Do Not Use, +1. Especially since Academia has cornered the market on almost all words ending in -ester, and the "periods into which the academic year is divided at some universities" varies, making the words less than useless to the rest of us because of the ambiguity.
    – Mazura
    Commented May 13, 2020 at 0:22

It's not in the most reputable dictionaries, but Wiktionary has it: quadrimester. It is a cousin of the more commonly used trimester, which means three months. It is composed of the Latin/French words for four and month.

  • 1
    Comments are not for extended discussion; this conversation has been moved to chat.
    – Glorfindel
    Commented May 14, 2020 at 5:50
  • Why are the chats not visible there? I mean the link shows, page not found. Commented Oct 19, 2020 at 7:55
  • @DhanishthaGhosh The room was automatically deleted for inactivity. I've saved a copy here.
    – Glorfindel
    Commented Oct 19, 2020 at 8:14

One-third of a year could work:

"For the first third of the year, sales were down. They picked up in the second period, but fell flat again in the final third."

It is works ok in this context, but 4 month period is probably clearer.

  • 2
    But note that it’s weird to track things like this using anything other than quarters.
    – Tim
    Commented May 12, 2020 at 11:33
  • "tertial (ˈtɜːʃəl) adj, n (Zoology) another word for tertiary [C19: from Latin tertius third, from ter thrice, from trēs three]" – TFD - tertiary isn't a noun, so you have to use ordinals. In Latin: tertius; English: third.
    – Mazura
    Commented May 13, 2020 at 0:16
  • @Tim, ? Why? Just because usa has a common word called "Quarter"?
    – Pacerier
    Commented Oct 28, 2023 at 15:29
  • @Pacerier no - in the US and other nations with similar standards, Generally Accepted Accounting Principles (or GAAP) is used for company financials. You’ll find that this will include things like using standardised time periods so companies can be compared historically and to one another. These periods are almost always 1/4 of a year (Q1-Q3), with some things being tracked as 1/2 a year (H1 and H2) and some being full year (FY)
    – Tim
    Commented Oct 29, 2023 at 16:39

Go with ...


Eight two-week periods ~= 4 months :D

  • 6
    Maybe a hexadeciweek.
    – towe
    Commented May 14, 2020 at 8:58
  • 2
    Very creative solution!
    – CasualBen
    Commented May 14, 2020 at 13:01
  • @towe if you're going that route, it should be a heptadeciweek since 4 months is 17.33.. weeks Commented May 14, 2020 at 16:14
  • 1
    @DanIsFiddlingByFirelight so novemfortnight is closer?? Doesn't have the same ring ;)
    – johnDanger
    Commented May 14, 2020 at 16:19
  • 2
    necroposting but it would be hexadecaweek or heptadecaweek, as deca means ten and deci means tenth. so a "deciweek" would be a tenth of a week, or 16.8 hours, or 0.7 days, making a "heptadeciweek" 117.6 hours or 4.9 days. you're welcome.
    – RML
    Commented Jul 5, 2023 at 20:30

I'm not sure I've seen a word searched so much and never found due to nonexistence. I'm searching too and found this post among others (which go back 15+ years). My context is an Income Statement for a firm (the sales example above is helpful in this regard). So I need a "label" that describes a 4-month period, or a unit of time that is distinct from other 4-month units of time. For a monthly income statement column heading, we simply say "Month: 1, 2, 3, 4, 5, ....or Jan, Feb, Mar, Apr...". For quarters we simply say "Quarter: 1, 2, 3, 4". But a business whose projects have a distinct 4-month lifespan, thereby generating 3 sequential spans per fiscal year (in my case a fiscal year is Jan through Dec U.S. tax year), or equal 4-month periods. I'm going with a statement heading of "Quad-monthly Income Statement" and my 4-month periods will be labeled "Period: 1, 2, 3".

  • However quad-monthly is 4x1, and not 12/3. They mean different things (on that, see my answer).
    – Pacerier
    Commented Oct 28, 2023 at 15:57

Your question seems self contradictory. You say, "'If I want to say the first three months of the year in one word, I would say "the first quarter".' Except, umm, "the first quarter" is three words and not one word.

The short answer to your question is: There is no commonly used word in English for a period of 4 months. I see some people have posted suggestions for an invented word that would mean this, but if you tried to use a made-up word, you would have to explain it or no one would know what you were talking about.

If you are just referring to this time period one or two times in some discussion, it would be far simpler to just say "a period of 4 months". Yes, that's 5 words instead of 1, but if you made up a new word, it would take more than 4 words to explain it, so you'd end up using more words, not less, not to mention being more confusing.

If you are writing a long article or a book in which you will repeatedly refer to a period of 4 months, then it could be useful to invent a word. If you use it often enough, the "overhead" of having to define it is spread across many uses and it may be worth the trouble.


There isn't a word in common use for a period of 4 months. But why would you need another word when you have the word "month"?

You asked if there was "a single word" - well, "month" is a single word, you just need to pluralise it and put the number four in front of it to show how many you mean.

Think about it - if there was a single word that meant "four months", you'd need to state how many of them you meant anyway, if not with a number then with the indefinite article "a". For example, in British English we do have a word meaning two weeks - we call it a 'fortnight'. You can say "a fortnight" or "two weeks" - both require using two words.

Words like "trimester" and "quarter" which mean three months are not really evidence that we should have a word for every quantity of months we might need to refer to. They are for specific things. For example, a 'quarter' of a year is always January-March, April-June, July-September, or October-December. It doesn't matter whether you are referring to a calendar year or a financial year, those are the quarters. You can't refer to the 3 months of Febuary - April as "a quarter". Likewise 'trimester' refers to three months of a specific term, such as a pregnancy or a school year. More importantly, a pregnancy trimester is 13 weeks, not 3 calendar months.

  • Saw a movie once where a character says, "We all agreed to continue for a fortnight. But we'll continue indefinitely, because none of us are exactly sure how long a fortnight is."
    – Jay
    Commented Oct 30, 2023 at 8:31

In cases where there are no words [yet] but you need one, it is not a stretch to invent one. People do invent words when they need one, even in "official" publications.

Of course, words are used in multiple contexts, so you first need to have a context in mind. Eg in writing:

Month: 1st, 2nd, 3rd, 4th, 5th, 6th, 7th, 8th, 9th, 10th, 11th, 12th.
Quarter: 1st, 2nd, 3rd, 4th.

..I will complete the pattern with any of the following:

Tri-ter: 1st, 2nd, 3rd.
Thirter: 1st, 2nd, 3rd.      //
Thirder: 1st, 2nd, 3rd.
Thirdth: 1st, 2nd, 3rd.
Thirth: 1st, 2nd, 3rd.      //

Eg 2 in writing:

I need it for half a year.
I need it for a quarter year.

..I will complete the pattern with any of:

I need it for thirth a year.      //
I need it for a thirter year.      //
I need it for a third a year.
I need it for one-third a year.
I need it for onethird a year.
I need it for 'third a year.
I need it for thirdth a year.

And if one can consider the candidates that are usable in multiple contexts to be superior.. Thus "thirth" or "thirter".

  • This would open a can of worms, people will either be asking if thirter and thirth were misspellings/ typos or something hallucinated by ChatGPT.
    – Mari-Lou A
    Commented Oct 28, 2023 at 16:23
  • @Mari-LouA, depends on context. How and where you use what.
    – Pacerier
    Commented Oct 28, 2023 at 16:34
  • It doesn't depend anything on context, it's a neologism and thirth and thirter, if anything, make me think of three months or thirty months, not four.
    – Mari-Lou A
    Commented Oct 28, 2023 at 16:39
  • @Mari-LouA, That's silly argument since, quar-ter makes you think of four months? You are simply too used to dividing by 4 and too unused to dividing by 3. so while (with some control) you may be able to think both x*4 and x/4, you can only think x*3 and never x/3.
    – Pacerier
    Commented Oct 28, 2023 at 17:06

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