Is this a bi-definition?

I am in the middle of writing an email to colleagues advising that we have regular meetings twice a week, and I think to myself, "Should I use the word biweekly in this case?" As I'm a little unsure, I google the word, and get numerous, dictionary website entries that explain that the word biweekly, means both:

• twice a week, and 
• once every two weeks.

For instance see: http://encarta.msn.com/dictionary_1861590876/biweekly.html

So would someone please explain to me how it is possible to use the word biweekly without it being unclear? The only possible way I could imagine using it is something like this:

"Hi guys. Don't forget our biweekly meeting tomorrow. That is, our meeting that is held every Tuesday and every Friday, that is twice-weekly, and not every second week on Friday."

It's enough to drive a man to drink. Oh. Don't mind if I do.