cham ‧ ber ‧ lain /ˈtʃeɪmbələn, ˈtʃeɪmbəlɪn $ -bər-/ BrE AmE noun [countable]
[ Date: 1100-1200 ; Language: Old French ; Origin: chamberlayn , from Old Saxon kamera , from Latin camera ; ⇨ ↑ chamber ]
an important official who managed the house of a king or queen in the past