The word Biennial means Every two years
biennial
Biennial means "occurring every two years," OR "lasting for two years." The word biannual can also mean "occurring every two years," although its most common meaning is "occurring twice a year."
Biannual. Biannual can mean occurring every two years, OR occurring twice a year. Biennial, on the other hand, means only the former: occurring every two years.
biannual A couple of years
Biannual~ this means twice in one yearbiennial~ this means once every two years
biennial
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.
The word is... bicentennial.
biennial and biannual, althou biannual could also mean twice a year
For example, something that happened in 1400, 1600 and 1800 happened every two hundred years.
The word "biennial" means an event that either lasts for two years, or it happens every two years.
Biennial or biannual can refer to something which happens every two years.
Bimonthly means every two weeks. One can tell by the word monthly which is included in the word bimonthly, giving this clear indication of what is intended.