case ‧ ment /ˈkeɪsmənt/ BrE AmE ( also ˈcasement ˌwindow ) noun [countable]
[ Date: 1400-1500 ; Origin: Probably from Old North French encassement 'frame' , from casse ; ⇨ ↑ case 1 ]
a window that opens like a door with ↑ hinge s at one side
case ‧ ment /ˈkeɪsmənt/ BrE AmE ( also ˈcasement ˌwindow ) noun [countable]
[ Date: 1400-1500 ; Origin: Probably from Old North French encassement 'frame' , from casse ; ⇨ ↑ case 1 ]
a window that opens like a door with ↑ hinge s at one side
Longman Dictionary of Contemporary English. Longman - Словарь современного английского языка. 2012