The totality of living organisms and their environment.
The part of the Earth and its atmosphere capable of supporting life.
The external covering at the top of a building.
The top external level of a building.
The upper part of a cavity.
An overhanging rock wall.
The surface or bed of rock immediately overlying a bed of coal or a flat vein.
To cover or furnish with a roof.
To traverse buildings by walking or climbing across their roofs.
To put into prison, to bird.
To shelter as if under a roof.