'baboon' originates from French, specifically the word 'babouin', where that French word referred to the animal now called a baboon.

'baboon' changed from French 'babouin' and earlier from Latin/Greek forms such as Latin 'babuinus' and Greek 'bábouinos', and eventually became the modern English word 'baboon'.

Initially it meant 'a doglike monkey' (as recorded in classical and medieval sources), and over time it has retained that zoological meaning while also gaining a figurative insulting sense referring to a coarse person.