Definition of "schpritzer"

One lever controls directionals, the two-speed wipers, headlight flasher and windshield schpritzer.

1966, Popular Mechanics, volume 125, number 1, page 230

He ordered a schpritzer for himself (it was a hot summer day) and after she'd finished her Collins, he asked if she wanted to order.

1966, Nicholas Samstag, Come and see my shining palace, page 268