'baronetise' originates from English, specifically formed from the noun 'baronet' plus the verb-forming suffix '-ise' (from French '-iser' or English '-ize').

'baronet' itself comes from Middle French 'baronnet', a diminutive of 'baron'; the verb 'baronetise' developed in Modern English by adding '-ize'/'-ise' to 'baronet' to mean 'to make a baronet.'

Initially related to the notion of a 'small or lesser baron' embodied in 'baronet', the verb came to mean specifically 'to grant the hereditary title of baronet' and has retained that specialized sense.