How can biweekly mean both "every two weeks" and "twice a week"?

It doesn't.

Bi-weekly = once every 2 weeks

Semi-weekly = twice a week

Google it. The internet doesn't lie.

IT CAN MEAN BOTH! THE INTERNET DOESN'T LIE!

Bi= twice

semi=half

So to be correct, it is biweekly- 2 x a week

and semi- monthly= every 2 weeks

No???

The meaning of bimonthly (and other similar words such as biweekly and biyearly) is ambiguous. Bimonthly, for instance, can mean either ‘occurring or produced twice a month’ or ‘occurring or produced every two months.’ So, if an organization holds bimonthly meetings, over the course of a year, will it meet six times or twenty-four times? The only way to avoid this ambiguity is to use alternative expressions like every two months and twice a month.

It gets easier as the timespan lengthens-

Biennial and biannual are often confused. Biennial means ‘occurring every two years’ (the biennial Ryder Cup tournament), while biannual means ‘twice a year’ (the solstice is a biannual event).

bi·week·ly

adjective \(ˌ)bī-ˈwē-klē\

: happening every two weeks

: happening twice a week

Technically it means twice a week. It's one of those things that is misused so commonly that some consider the erroneous usage to be acceptable. Very similar to "could care less". I guess that is how languages develop.

People shouldn't use it as twice a week.

Twice a week: semi-weekly

Every other week: bi-weekly

Twice a month: semi-monthly

Twice a year: semi-annual

Every two years: bi-annual (like the world championships)

Half of the people posting here: bi-polar

The other half: effort-weakly

Bi-weekly is confusing. Just say fortnightly.

I once heard two people debate the difference between biannual and biennial. One of them was correct, I suppose, but after a while, I was not rooting for either.

The dual meanings of bi-weekly are a problem that should be solved by someone responsible for such things. Pick one and stick with it.

I think that you are confusing the term 'bi-weekly' with its synonym, 'annual'.

As in, Mountain View's Annual Art & Wine Festival (which comes up every two weeks).

Wished I Was Running wrote:

I once heard two people debate the difference between biannual and biennial. One of them was correct, I suppose, but after a while, I was not rooting for either.

Biannual means twice a year.

Biennial means once every two years.

So it has been picked. So you shall stick with it.

Is that anything like raising a building or razing a building?

What about the difference between a bisexual and a semisexual?

I would have assumed we all knew what biweekly meant and what semi-weekly meant and that they were two very different things, but gosh, apparently not.

Wossamotta wrote:

I would have assumed we all knew what biweekly meant and what semi-weekly meant and that they were two very different things, but gosh, apparently not.

You assume too much.

im a penguin not a joker wrote:

Is that anything like raising a building or razing a building?

Yes

At one time they did not mean the same thing, but they have come to mean the same thing.

I go with the old school version that bi weekly is every other week.

it is a result of dumbifcation ... at one time, words had meaning.

retards are reproducing like cockroaches.

look at the use of there, their, they're ... all horribly misused day in and day out.

mcflounder wrote:

look at the use of there, their, they're ... all horribly misused day in and day out.

But in that case the dictionary has it correct.