service window, ticket window, car window
Estuve en la cola del banco durante casi dos horas porque solo había una ventanilla abierta.
I was in the bank queue for almost two hours because there was only one window open.
La llamé porque vi el auto abierto con la ventanilla rota.
I called her because I saw the car open with the window broken.
— O Som ao Redor (2012)
Quiero un asiento de ventanilla.
I want a window seat.
Ni se acercó a alguna ventanilla, desde la que se viera el Océano.
He didn't even go near any window from which the ocean could be seen.
— Solaris (1972)