indiction
/ɪnˈdɪkʃən/noun
1- historical a fiscal period of fifteen years used as a means of dating events and transactions in the Roman Empire and in the papal and some royal courts. The system was instituted by the Emperor Constantine in AD 313 and was used until the 16th century in some places.〈史〉15年一度的财政期（罗马帝国、罗马教廷和一些宫廷中以此来编年、纪事, 公元313年由君士坦丁大帝创立, 在一些地方沿用至16世纪）。
1.1
- with numeral a particular year in such a period15年财政期中的某一年。
词源
from Latin indictio（n-）, from the verb indicere （see INDICT）.