|a minor or unimportant street, esp one leading off a main thoroughfare|
|the offspring of a zebra and a donkey.|
|a stew of meat, vegetables, potatoes, etc.|
A minor thoroughfare that carries little traffic, as in Our favorite hotel is on a quiet little side street. The side in this idiom means "off to one side, away from the main street." [c. 1600] Also see back street.