Something that occurs TWICE a month is called SEMI monthly (semi=half) and something that occurs every TWO months is called BI-Monthly (BI=TWO)
The prefix "bi-" means occurring twice in a given period. Therefore, a word that signifies happening twice a year could be "biannual."
"bi" means two and "centi" means hundred and "anual" means year. so bi-centen-nial means "every two hundred years."
Biannual biannual means twice per year. Biennial means every two years or every other year.
It means twice a month. For example, we pay our water and electricity bills bi-monthly.
bi monthly is once every two months.
Semi-Monthly means twice per month. Bi-weekly means every two weeks. A Semi-Monthly cycle occurs 24 times per year. A Bi-Weekly cycle occurs 26 times per year.
Biennial is a word describing an event that happens every two years.
The word you are looking for is biennial. It does not mean a person who will have sex with anyone but only once every two years.
Bicentennial means it has happened yearly for 200 years or once every 200 years. Bi- (dual, two) cent- (100, 1/100)
semi-annually - happening every half year bi-annual - coming twice a year NOT biennial - happening every two years
Every two weeks.