'pro-feudalism' is a compound of the prefix 'pro-' and the noun 'feudalism'. 'Pro-' originates from Latin 'pro', meaning 'for' or 'in favor of', while 'feudalism' comes from Medieval Latin 'feudalis' (related to 'feodum'), referring to a fief or feudal tenure.

'feudalism' traces back to Medieval Latin 'feodum' (a fief), which passed into Old French (e.g. 'foi'/'feu' forms) and Middle English as terms referring to land tenure and obligations; it later developed into the broader modern English noun 'feudalism'. The prefix 'pro-' remained from Classical Latin into English via Old French/Latin borrowings.

Originally the root 'feodum' meant a specific fief or landholding; over time the related terms grew to denote the wider social, legal, and political system based on such land-tenure relations. Combining with 'pro-' yields the modern sense of being 'in favor of' that system.