The characters of the civilization described on this Wiki do not speak English, but, rather, various pony languages. Thus, all of the names and terminology used is notionally "translated from the Equestrian" (or some other language.) The notional translation is usually idiomatic and follows dynamic equivalence rather than a literal translation. For example, since ponies were historically a matriarchal society, words like "Kingdom" are probably literally "Queendom" and the gender-unmarked of terms like "duke" probably means a female noble ruler, not a male.
Translation convention is also the explanation used for when someone makes an inappropriate pop culture reference in-character; it's assumed to have been an equivalent reference for the pony culture. Please try to avoid dependence on this concept, especially as you miss an opportunity to 'ponify' the pop culture reference explicitly, perhaps with a clever Horse Pun.