'Muscovian' originates from Latin (via Medieval Latin and early modern usage), specifically the word 'Muscovia', where 'Muscov-' referred to the region around Moscow.

'Muscovian' changed from the Medieval/early modern form 'Muscovia' (from Latin and Western European references to the Russian realm), and by addition of the adjectival suffix '-ian' it became the modern English 'Muscovian'.

Initially, it meant 'of or relating to Muscovy' (the historical state centered on Moscow), but over time it evolved into its current meaning of 'relating to the modern city of Moscow or its inhabitants'.