Definition of bi-monthly

We are having an internal debate and really decided to take it to the masses.  Completely unrelated to what we actually do, but for the benefit of our clients and the hopes of overturning the definition in Webster we are petitioning you to help us fight the good fight.

According to Webster and – bi-monthly means twice a month AND once in every two months. We want to stop the madness. Help us overturn the definition – pick a side and stand by it.

Tell us what bi-monthly means to you if you had to choose:

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Liberty Tsighis

Liberty Tsighis is the owner of Liberty Interactive Marketing, a Los Angeles digital marketing agency. She specializes in digital marketing strategy and content marketing. Foodie from birth, wine lover and family addict you can find her on , Twitter and Instagram.


18 Responses to “Definition of bi-monthly”

  1. sietsema Says:

    I think it’s both. However, if I had to choose one, I’d say…

    bimonthly is every other month
    semi monthly is twice a month (or more)

    Question: what is bi-weekly?

  2. admin Says:

    Thanks Sietsema for adding to our pain and agony by adding in “what is bi-weekly?” Baby steps, baby steps. Will it ever end?

  3. john Says:

    What about bi-sexual ?

  4. Mike Swan Says:

    It is definitely every two months. Bi means two, not half, as in bicycle (two wheels) and biped (two feet, or whatever).

    In response to the biweekly question, is every two weeks. The most common scenario here is with paychecks if you are paid biweekly you are paid for instance, every other Friday, so in certain cases you may get three paychecks in a month. August 2008 would be a good example of this, since there are 5 Fridays.

    Semi-monthly is twice a month based on a particular date as in the 5th and 20th, regardless of the number of days in the month and how they fall.

    In the grand scheme of things, biweekly often works out to an extra paycheck a year versus semi-monthly.

  5. Liberty Says:

    Thanks everyone! Keep up the good work. We are at 147 votes.

  6. CBrugnolotti Says:

    how hard is this?
    bi-weekly (every other week)
    bi-monthly (Every other month)

    its like calling a millimeter a meter.

  7. websters Says:

    […] means both twice a month and once every two months… Seriously. What do you think? Poll it up! […]

  8. Marcii Says:

    Semi-monthly would be once every two months. Bi-monthly should be twice a month.

  9. A Says:

    Bi-weekly is every 2 weeks
    so bi-monthly is every two months

  10. Liberty Says:

    Hi everyone, we’re at 292 votes. Keep ’em coming! Thanks for your support.

  11. Shizuka Says:

    Voted for ‘twice a month’ going on the analogy of ‘bisecting an angle’ and thereby splitting in two.

    However, semi-monthly may hold a stronger argument for that position, as semi- implies less than the suffix.

    Finding it amusing that the vote is barely in favor of ‘twice a month’, even though most of the common sense arguments in the comments would point to ‘every two months’.

  12. Marjorie Says:

    It ca not be both definitions since they are very different. it is the former if you look at it by defining the segments of the word

  13. Maggie Says:

    It’s all in the perception of the language. If “bi” means two, then bi-weekly could mean 2 times per week and bi-monthly could mean 2 times per month.

  14. Nero Says:

    Allow me to weigh in on this discussion/debate.

    There is no ambiguity in respect of the meaning of “biannual”.”Biannual” means “TWICE per year”, that is, “TWO TIMES per year”. NOW THAT WE HAVE ESTABLISHED A PLATFORM OF AGREEMENT, let us proceed.
    We are correct: The prefix, “bi-“, means “two” OR “twice”(depending on the sense of its usage).

    Originally/classically, “bi-monthly” was ascribed the meaning, “occurring TWO TIMES per MONTH” or “occurring TWICE per MONTH”. This was not to have been confused with “SEMI-monthly”, which means, “occurring once every HALF-month”.
    Follow me closely now. If events, P and Q, occurred on March 27, 2009 and March 28, 2009, respectively, then they occurred TWICE PER MONTH, but P and Q would not have occurred SEMI-monthly, since the interval between the occurrences of the two events was NOT HALF of a month. Hence, “semi-monthly events” ARE “bi-monthly events”; but “bi-monthly events” are NOT NECESSARILY “semi-monthly events”.

    Ah. You are still with me. Beautiful.

    Finally, because language is dynamic and the meaning of a “word” is arbitrary, the meaning ascribed to a word may change, depending on widespread its use is deemed to be. Lexicographers, therefore, later agreed that BECAUSE OF THE WIDESPREAD, POPULAR DEVIATION IN USAGE FROM THE CLASSICAL MEANING OF “BI-MONTHLY”, THE SUBSEQUENT (mis)USAGE WHICH MEANS “occurring ONCE every TWO MONTHS” SHOULD BE EMBRACED.

    CONCLUSION: “Bi-monthly”, originally meant “occurring TWO TIMES per MONTH”;
    “Bi-monthly” was later also taken to mean “occurring ONCE every TWO
    MONTHS” because of popular deviation from the original meaning.

  15. soluna Says:

    As fortnightly means once every two weeks, then bi-weekly must surely be twice a week; hence I think I have to go for bi-monthly as being twice a month. I do like the explanation given by Nero, though must admit I have never used or heard the term “semi-monthly”

  16. Jen Says:

    I don’t agree with Nero. Biannual is not exclusively twice per year. It also means every 2 years, for example, the Venice Biennale.

  17. Ikenna Says:

    What is the meaning of bicycle? Is means 2 cycles(wheels) in one device. What is d meaning of tricycle? Is means 3 cycles(wheels) in one device. Granted. What is the meaning of bisexual? Is means two sexual habits in one organism. What is d meaning of biconcave; it means 2 sides(parts) in one object. What is the meaning of say, a bimonthly report? It means 2 months events rendered in one report. The list can go on.

    Let there be no confusion; bimonthly means every two months and same goes for biweekly.
    Sorry for droping in so late. Rgds.

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