window-side seat
Refers to a seat next to a window, commonly in restaurants, trains, or airplanes.
窓際の席を予約したいです。
I'd like to reserve a window-side seat.
飛行機ではいつも窓際の席を選ぶ。
I always choose a window seat on airplanes.
Compound of 窓際 (window-side) and 席 (seat).