[ trahy-week-lee ]
/ traɪˈwik li /
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every three weeks.
three times a week.


occurring or appearing every three weeks.
occurring or appearing three times a week.

noun, plural tri·week·lies.

a triweekly publication.



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Origin of triweekly

First recorded in 1825–35; tri- + weekly

Words nearby triweekly

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2021


What does triweekly mean?

Triweekly is commonly used to mean one of two things: once every three weeks or three times per week.

It can be used this way as an adjective, as in a triweekly meeting, or an adverb, as in We plan to meet triweekly. 

Yes, you can sometimes figure out what triweekly means from the context of the sentence. But not always. The term triweekly meeting might mean that it happens three times a week or every three weeks—both senses of the word are commonly used. Here’s the best (and maybe only) way to be perfectly clear: just say “three times a week” or “once every three weeks.”

Triweekly can also be used as a noun referring to a publication that’s published three times per week or once every three weeks (as opposed to a daily or weekly, for example).


  • New episodes of my triweekly podcast come out every Monday, Wednesday, and Friday.
  • Let’s plan to meet triweekly, on every third Thursday.

Where does triweekly come from?

The first records of the word triweekly come from around 1830. The prefix tri- means “three” or “three times.” The suffix -ly, which usually forms adverbs, is used in triweekly to mean “every.” It’s used in the same way in several other units of time, including hourly, daily, monthly, and yearly.

Different prefixes can be added to weekly to indicate a different period of time, such as in biweekly (every two weeks or two times a week) and semiweekly (twice a week). Triweekly is probably less commonly used than biweekly, but it has the same potential to be confusing. When triweekly does describe something that happens three times a week, chances are that it happens on Monday, Wednesday, and Friday (but you should probably still double—or triple—check).

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What are some other forms related to triweekly?

  • triweeklies (plural noun)

What are some synonyms for triweekly?

  • every three weeks
  • three times a week

What are some words that share a root or word element with triweekly


What are some words that often get used in discussing triweekly?

How is triweekly used in real life?

Triweekly is used to mean both “three times a week” and “every three weeks.” To avoid confusion, it’s a good idea to clarify exactly which one you mean.



Try using triweekly!

Is triweekly used correctly in the following sentence?

We plan to publish triweekly, on the first of every month.

Example sentences from the Web for triweekly

British Dictionary definitions for triweekly

/ (traɪˈwiːklɪ) /

adjective, adverb

every three weeks
three times a week

noun plural -lies

a triweekly publication
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012