Let’s (try to) end the debate: Does biweekly mean twice a week or twice a month?

A dictionary search for biweekly probably won’t clear up the confusion about how often a biweekly meeting is held.

Merriam-Webster, Dictionary.com, and Cambridge Dictionary each offer two different definitions for the adjective: occurring twice a week or every two weeks. The enigma of language goes beyond the fortnightly; Bimonthly and semiannual also have competing definitions. Is the bimonthly meeting twice a month or bimonthly? Is the biannual family meeting twice a year or once every two years?

The different definitions have left people – even those who work with dictionaries – scratching their heads for a long time.

“This is absolutely an English problem, but we generally don’t have a good tool for this,” said Merriam-Webster editor Peter Sokolowski. “It is strange that bi, which means two and twice, is confused with itself. It is an unusual circumstance from a linguistic point of view.”

People search the Merriam-Webster website bi-weekly, bi-monthly and semi-annually frequently, Sokolowski said.

“A lot of the tension we feel is because of new words or slang or things like that, but really, it’s those kinds of words that are the bread and butter of the dictionary,” Sokolowski said. “You know, those ambiguities of English that drive people to the dictionary day after day, year after year.”

The Associated Press, which guides the style choices of many news organizations, has taken a stance on the definition it uses. It says biweekly means every other week and semi-annual means twice a week.

In everyday life, Sokolowski advises providing context whether you plan to say biweekly, bimonthly, or semi-annually. Or just work around it – say, twice a week, twice a month, and so on. Laurel MacKenzie, associate professor in the Department of Linguistics at NYU, agrees.

“Sometimes you just have to paraphrase because it can be totally ambiguous without context,” she said.

Michael Adams, an English professor at Indiana University, said that bringing back the word fortnight, a period of 14 days, and the word fortnightly, something that occurs once every 14 days, would solve many of biweekly’s problems.

“So if we’re looking for a solution to the problem, let’s go back to biweekly and biweekly,” Adams said. “And then we don’t have to worry about the fortnightly or bimonthly meaning of two things, or the biannual or biannual insertion that users clearly, from the historical record, don’t prefer.”

A review of the Corpus of Historical American English, which can be used to determine how often a word is used compared to other words, shows that fortnight and fortnight have been used more frequently than fortnightly and that fortnightly in turn , has been used more frequently than bi-annually, Adams said.

“This is the result of fortnight being an old English word so well established historically that people saw no reason to use biweekly to mean every two weeks,” Adams said.

Although biweekly and biweekly were used much more frequently historically than biweekly, their use began to decline somewhat after the 1950s, Adams said.

And although the ambiguous definition of biweekly has confused people for a long time, dictionaries have not decided to limit themselves to just a single definition.

“The basic issue is that language is not mathematics,” Sokolowski said.

Instituting a language change and getting people to follow it is a challenge, MacKenzie said. When language changes, it is usually to be more equitable in the way terms are phrased.

“It’s very difficult for someone to litigate or legislate the language,” she said.