can mean either this dictionary biannual Biannual http://www.merriam-webster.com/dictionary/biannual biannual http://www.merriam-webster.com/dictionary/biannual can mean either can mean either biannual (or biennial) http://www.merriam-webster.com/dictionary/biannual Biannual http://www.merriam-webster.com/dictionary/biannual