1. occurring or happening once every two years
2. lasting for two years

1. a plant that completes its life cycle in two years, producing leaves in the first year and flowers and seeds in the second

Examples

• The biennial conference brings together researchers from around the world every other year.
• Carrots are biennials that store energy in their roots during the first year.
• The city holds a biennial art festival in even-numbered years.
• Many vegetables like cabbage and beets are biennials.
• The biennial report covers the activities of the past two years.
• Biennials require two growing seasons to complete their reproductive cycle.