I used to go out with a poet, and she helped put out this poetry chapbook. It came out triannually, and that was the first time I knew that triannual meant thrice a year, rather than once every three years, which is triennial. Likewise biannually and biennially – twice a year and every two years, respectively. EXCEPT that, according to this dictionary, the second definition of biannual IS biennial. This both hurts my head and breaks my heart.
I KNEW this was a problem with biweekly, which means both twice a week AND every two weeks. This was a tad confusing when wanting to order comic books back in the day. We assumed, though, that a comic was going to come out twice a month, rather than eight or nine times a month. To avoid this confusion, I started using the term fortnightly for every two weeks. The problem with THAT is Americans have no idea what a fortnight is.
In the triannual definition, the usage note reads: “To avoid confusion between ‘triennial’…and ‘triannual’…, it is often better to substitute a less ambiguous phrase such as ‘three times a year’ or ‘every four months’. I suppose so, but often the phrase is far less elegant than a single, perfect word. Obviously, triannual has been rendered an imperfect word.
For twice a year, I use semiannual, but I don’t have a similar option for thrice annually.
Two of my favorite words denoting the passage of time:
Sesquicentennial – 150 years. Find more anniversary words here.
Lustrum – five years, which was tied to the census of ancient Rome.
What’s The Frequency, Kenneth? – R.E.M.
8 New Punctuation Marks We Desperately Need, says College Humor.