'banqueteer' originates from French/English elements: from French 'banquet' (itself from Italian 'banchetto', a diminutive of 'banco' meaning 'bench' or 'table') plus the agentive suffix '-eer' (from Middle French '-ier'), where '-eer' indicates 'one associated with' or 'one who does'.

'banquet' came into English from Old French/Middle French (and from Italian 'banchetto' meaning 'small bench' used for a table); English formed the agent noun with the suffix '-eer' (from Middle French '-ier'), producing 'banqueteer' in Modern English usage.

Initially related to 'banquet' (a meal or feast) and thus referring generally to someone associated with a banquet (host or participant); over time it has come to be used chiefly for 'one who feasts' or 'a banquet attendee' and occasionally for a host who gives banquets.