semi-annual
adjective /ˌsemi ˈænjuəl/
  /ˌsemi ˈænjuəl/,  /ˌsemaɪ ˈænjuəl/
(North American English also semiannual)
 (especially North American English)- produced or happening twice each year synonym biannual
- The journal is published on a semi-annual basis.
 - the company's semiannual report