Semiannual, biannual, biennial

Posted by ESC on November 09, 1999

In Reply to: Meaning of word posted by Bob on November 08, 1999

: : Does anybody know how/why we use the term "Bi-annual"? In the dictionary it means twice a year but prefex "Bi" always means two....Bicycle, biplane, bisexual etc. etc.. To me Bi-annual should mean every 2 years. Is there a term I am unaware of that expresses every 2 years?

: biennial

According to my trusty "Associated Press Stylebook": "SEMIANNUAL- Twice a year, is a synonym for BIANNUAL. Do not confuse it with BIENNIAL, which means every two years."

Hmmm. I didn't know there was a biannual AND a biennial.

But sure enough, my dictionary says biannual or semiannual takes place twice a year. Biennial is an event that takes place every two years. (Every other year?)

BUT if you're talking about plants, "When is a Pig a Hog?" by Bernice Randall says: an ANNUAL is a plant that reaches maturity and completes its lifecycle in one season. Only blooms once and then it's gone. A PERENNIAL continues to bloom each year. A BIENNIAL plant lives for two years and usually blooms in the second year.

I have a headache now and I'm going to take a nap.