This is a quick post, but at a recent meeting at work the question about year-based cyclical adjectives came up. Me and another colleague did a little research and came up with some answers.
“Biannual” – occurring two times a year (“semiannual” seems to have the same meaning but it doesn’t feel as accurate to me)
“Triannual” – occurring three times a year
“Quadannual” – occurring four times a year (most people use the more elegant “quarterly” instead)“Biennial” – occurring once every two years, or lasting two years
“Triennial” – occurring once every three years, or lasting three years
“Quadrennial” – occurring once every four years, or lasting four years
This is more for my benefit that anything else because I’m bound to forget these. I tried to come up with some shorthand way of remembering the governing rule but I think I got distracted, Up-squirrel-style: