A boulevard is a type of broad avenue planted with rows of trees, or in parts of North America, any urban highway.
Boulevards were originally circumferential roads following the line of former city walls.
In North American usage, boulevards may be wide, multi-lane thoroughfares divided with only a central median.
The word boulevard is borrowed from French. In French, it originally meant the flat surface of a rampart, and later a promenade taking the place of a demolished fortification. It is a borrowing from the Dutch word bolwerk 'bulwark'.