1. Occurring every second year
   - biennial 
2. Occurring or payable twice each year
   - semiannual, biannual, half-yearly

1. Every two years
   - biennially 
2. Twice a year
   - semiannually

See also: periodic, periodical

• Iraqi Kurdistan
• Iraqi monetary unit
• Iraqi Mukhabarat
• Iraqi National Congress
• irascibility
• irascible
• irascibly
• irate
• irately
• ire
• Eurocentrism
• Eurocrat
• Eurocurrency
• Eurodollar
• Euroland
• euronithopod
• Euronithopoda
• Europa
• Europan
• Europe
• European
• European ash
• European barberry
• European bean
• European beaver