biyearly
adjective
bi·year·ly (ˌ)bī-ˈyir-lē 
1
: biannual sense 1
2
: biennial sense 1
Example Sentences
Recent Examples on the Web This week, the Japanese retailer has released the 10th edition of Uniqlo U, a biyearly collection crafted by French designer Christophe Lemaire and his partner, Sarah-Linh Tran. 
Barry Samaha, Harper's BAZAAR, 10 Mar. 2021
Barry Samaha, Harper's BAZAAR, 10 Mar. 2021 Word History
First Known Use
circa 1909, in the meaning defined at sense 1