noun
: a year of a sovereign's reign dating from the moment or anniversary of the moment of accession
the first regnal year of George V was from May 6, 1910 to May 5, 1911
— used especially in the citation of laws
noun
: a year of a sovereign's reign dating from the moment or anniversary of the moment of accession
the first regnal year of George V was from May 6, 1910 to May 5, 1911
— used especially in the citation of laws
Webster's New International English Dictionary. Новый международный словарь английского языка Webster. 2012