Biweekly has two accepted meanings in standard English, and that is what makes it confusing. It can mean every two weeks, but it can also mean twice a week.
For example, a company might say, Employees are paid biweekly. In that context, people usually understand it as every two weeks. But a gym schedule that says, Biweekly yoga class, could be understood as twice a week.
Because both meanings are widely used, context matters. The surrounding words often make the intended meaning clear, but not always.
- Every two weeks: The team meets biweekly on Fridays.
- Twice a week: She attends biweekly tutoring sessions.
If clarity matters, it is often better to choose a more exact phrase, such as every two weeks or twice a week. That avoids confusion and helps readers understand the schedule right away.