Furthermore, the AP style guide specifically defines “biannual” to mean every two years. Here it is from my edition:
Do you mean “specifically defines “biennial” to mean every two years”?
:smack:
Actually, I meant to write “specifically defines ‘biannual’ to mean every six months.”
At any rate rate, if the publication is edited by copy editors for a publication that is based on the Associated Press Stylebook (which is most American editorial publications and news services, although individual companies may have their own tweaks to the Associated Press guidelines), then “biannual” is proscribed to mean one thing only: occurring every six months. Now, to avoid potential confusion, the copy editor does have the option of changing it to “semiannual” or, simply, “twice yearly” (or similar), but “biannual” is absolutely kosher, too.