The roundness or ball-like shape of something.
Sphericity makes people think of balls, planets, and smooth things.
Examples:
The sphericity of the ball makes it easy to roll.
The sphericity of the Earth makes it look like a ball.
The sphericity of the marble makes it perfect for rolling.
The sphericity of the water droplets makes them look like tiny balls.
The sphericity of the sun makes it look like a giant ball in the sky.
The sphericity of the moon makes it a perfect sphere.