The term "semiyearly" refers to something which occurs twice a year. However, if you are searching for synonyms for the word "more semiyearly", it is likely that you are looking for a term which refers to something that occurs more frequently than twice a year. In this case, some suitable synonyms might be "bi-monthly", "fortnightly", "twice-monthly", or "semi-monthly". Each of these terms refers to an event or occurrence that takes place multiple times within a single month or every other week. So, depending on the frequency you are looking for, you can choose from these synonyms to best relate the intended meaning.