… and I hate the English language!
For every question, there is an answer. Just don’t think that you’ll necessarily like that answer. For example, I wanted to know if bi-monthly meant twice a month or every two months.
Unfortunately, it means both. As AskOxford says:
I’m afraid it means both! But in the publishing industry, it is used fairly consistently to mean ‘every two months’. The same ambiguity affects biweekly and biyearly. If you want to be absolutely clear, use a phrase such as ‘twice a week’ or ‘every two years’.