'non-Muscovite' originates from the English prefix 'non-' and the noun 'Muscovite', where 'non-' meant 'not' and 'Muscovite' denotes a resident or native of Moscow.

'Muscovite' entered English via French 'Moscovite' (and Medieval Latin 'Moscovia'), ultimately from the Russian place name 'Moskva' (Moscow). The negative prefix 'non-' comes from Latin 'non' meaning 'not'; combining them produced the modern English compound 'non-Muscovite'.

Initially, 'Muscovite' meant 'a resident or native of Moscow'; by adding the productive English prefix 'non-' the compound came to mean 'not a resident of Moscow', a straightforward negation that retains the original sense of 'Muscovite'.