One for the Scrabble board: biweekly...

From the Free Dictionary:

bi·week·ly (bī-wēk′lē) 
adj. 

1. Happening every two weeks.
2. Happening twice a week; semiweekly. 
n. pl. bi·week·lies
1. A publication issued every two weeks. 
adv.
1. Every two weeks.
2. Twice a week; semiweekly. See Usage Note.

Yes. It is a word. Perhaps only used in the USA, but it is a word nonetheless.

Biweekly = fortnightly.

Done. Easy. Every two weeks. Biweekly. I may have referred to the word previously, but as I am now being paid biweekly, I thought it was time to formally include it.