Damn English language

Word of the day: con-fused (verb) To fail to distinguish between; associate by mistake; confound:

While typing an email at work today, I wanted to use the word “biweekly” but I couldn’t remember if it meant twice a week or every two weeks. Upon asking a co-worker, I was met with the same confusion and she also mentioned the word “bimonthly” and what it actually meant.

Thankfully, we live in the internet age, so off to dictionary.com I went. First, I checked “biweekly”. Here’s what I got:

–adjective
1. occurring every two weeks.
2. occurring twice a week; semiweekly.

I then checked “bimonthly”. This came up:

–adjective
1. occurring every two months.
2. occurring twice a month; semimonthly.

HOW IS THIS POSSIBLE?!

Now, it was my understanding that “twice a week” and “every two weeks” were actually two different things, since, you know, something happening twice a week runs on a different schedule than something happening every two weeks. So if I told you I wanted to start a biweekly knitting club, how often do you think we would meet to knit?

How can one word mean two very different things?!?!?!

And if “semiweekly” means “occurring twice a week”, then why not have “biweekly” mean “every two weeks” and “semiweekly” mean “twice a week”?

I just do not understand.

(I also checked AskOxford.com and got the same results. Bah.)