(uncountable) Alternative spelling of Western Hemisphere / Used other than figuratively or idiomatically: see western, hemisphere.

(historical) Either of a pair of large copper hemispheres, with mating rims, that were used to demonstrate the power of atmospheric pressure. When the rims were sealed with grease and the air was pumped out, the sphere contained a vacuum and could not be pulled apart even by teams of horses.

(uncountable) Alternative spelling of Northern Hemisphere / Used other than figuratively or idiomatically: see northern, hemisphere.

(uncountable) Alternative spelling of Southern Hemisphere / Used other than figuratively or idiomatically: see southern, hemisphere.

The hemisphere of the Earth which is almost completely covered in water.

The hemisphere of the Earth in which most of the continents are gathered