Frequently Asked Questions
Words
Does bimonthly mean 'twice a month' or 'every two months'?
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'.
source:
http://www.askoxford.com/asktheexper...ords/bimonthly