Biannual
Biannual is a truly awful word and refers to either something happening once every two years, or on the other hand, twice in one year. In the beginning, its meaning was "one every two years" from the Latin bi, meaning "two, twice". However, in kind with many other Greco-Latin words (and wordbits), its meaning became blurred. This kind of muddling can be seen in the word "dialog", which means a talking between two or more folk, from the Greek dia, meaning "across". But this has become confused with "di-" (meaning two), giving rise to the untrue idea that a dialog is a talk between two men.
This word, and its mate "biennial" (which was brought in to "clear up" the muddle), stand as examples of the madness behind using Greco-Latin roots when home…