A more thorough explanation:

Definition: Biennium refers to a period of two years. It is commonly used by state legislatures to make appropriations.

• The budget for the state's education department is set for the upcoming biennium.
• The city council plans to allocate funds for road repairs during the next biennium.

These examples illustrate how biennium is used to refer to a two-year period, particularly in the context of budget planning and allocation by state legislatures and local governments.