Late Middle English. Originally from Anglo-Norman chambellein, chambelleyn, Anglo-Norman and Middle French chambellain, variants (with assimilation of -rl- to -ll-) of chamberlain, chambrelain, etc. In later use reborrowed from French chambellan, originally a variant (with assimilation of -rl- to -ll-) of chamberlain, chambrelain, etc., which later became the dominant and now standard French form.