"Sir Paul Gavrilovich Vinogradoff" is a proper noun which cannot be replaced with a synonym. It refers to a prominent Russian historian and jurist who lived from 1854 to 1925. Vinogradoff was a pioneer in the study of medieval law and a significant figure in the field of comparative law. He made several important contributions to legal history, including the theory of legal pluralism and the analysis of customary law. Vinogradoff was also a prolific writer and published numerous books and articles during his career. Therefore, there can be no synonym for the name "Sir Paul Gavrilovich Vinogradoff" as it is a unique identifier for this remarkable historical figure.