None of my Russian dictionaries even has a listing for the "tsarina" spelling, all only list "tsaritsa" - wife of a tsar.
My Webster's dictionary lists both words, but under "tsaritsa" it simply has, as the definition: = tsarina.
There could be some finer point to the definitions of these two words that I don't know about.... it's just that I've been unable to find it in several dictionaries, nor in my encyclopedia.
In any case, Ivan the Terrible was a real "zhopa".