Biweeksly (adjective): Used to indicate that
something occurs once every two weeks, as opposed to biweekly, which indicates that
something occurs
twice in one week. (This helps to resolve the issue of the otherwise ambiguous usage of the word biweekly.)
Person A: So the event is held biweeksly.
Person B: You mean biweekly?
Person A: No, the s is on
purpose, it's supposed to indicate a
plural of weeks, as in this event is held once every two weeks.
Person B: Oh! That's great! Because otherwise I was just going to have to
ask you to clarify what you meant by biweekly!