'seigneurial' originates from French, specifically the word 'seigneur', where 'seigneur' meant 'lord' (ultimately from Latin 'senior' meaning 'older').

'seigneurial' entered English via Middle French/Norman usage: Old French forms such as 'seignor'/'seigneur' developed into Middle French 'seigneur', and English adopted the adjective form as 'seigneurial' (and variants) during the Middle English/early modern period.

Initially associated with the idea of an 'older' or senior person (from Latin 'senior'), the sense shifted in French to denote a territorial lord; in English it came to mean 'relating to a seigneur or seigneury', retaining the lordly/manorial sense.