Greenbelt (noun)

1. An area of protected open space surrounding a city or town.
2. A belt of grass or other vegetation surrounding a built-up area.

Origin:

Compound of green + belt.

Examples:

1. The city's greenbelt is a popular spot for hiking and picnicking.
2. Developers are trying to build on the greenbelt, but the city council is fighting to protect it.
3. The greenbelt provides a natural barrier to urban sprawl.
4. Greenbelt is a conservation area that surrounds the city to maintain the ecological balance.
5. I love to take long walks in the greenbelt on a sunny afternoon.