Half yearly is a commonly used term when referring to events or activities that happen twice a year. However, there are many synonyms that can be used in place of this term. For example, the phrase "biannual" means occurring twice a year and is often used in academic or business settings. "Semi-annual" is another popular synonym for half yearly and is frequently used when referring to financial reports or sales projections. Additionally, the terms "biennial", "semi-yearly", and "biyearly" can all be used to denote events or activities that happen twice a year. Regardless of which term is used, the meaning remains the same: things occurring twice annually.