biyearly
1. [ adjective ] occurring every second year
Synonyms: biennial
Examples:

"they met at biennial conventions"

Related terms: year year
2. [ adverb ] every two years
Synonyms: biennially
Examples:

"this festival takes places biennially"

Related terms: biennial biennial
3. [ adverb ] twice a year
Synonyms: semiannually
4. [ adjective ] occurring or payable twice each year
Synonyms: biannual semiannual
Related terms: year year year