I pay my mother-uckin' rent fortnightly

We get paid every two weeks, which my company calls biweekly. I had always assumed biweekly meant 'twice a week', but I had finally accepted the fact that perhaps I was wrong. Well, today I looked it up on merriam-webster.com. Annoying fact: IT MEANS BOTH. What a crappy word!! There is no way to distinguish between 'twice a week' and 'every two weeks'?! There should definitely be two separate words. I can't even imagine a scenario in which the ambiguous word could be used unambiguously. You would pretty much have to put the definition in the sentence, which defeats the purpose of having the word. I propose to you, fellow speakers of American English, that we adopt the word fortnightly to mean 'occurring every two weeks' (it does mean that, and who doesn't want to sound like Flight of the Conchords in their everyday speech?) and use biweekly only to mean 'occurring twice a week'. Cool?