Gravity (noun)

1. The force by which a planet or other body draws objects toward its center.
2. A state of being weighty or serious.

Origin:

Late middle english: from latin gravitas, from gravis 'heavy'. the scientific sense dates from the early 17th century.

Examples:

1. The moon's gravity is one-sixth that of the Earth's.
2. The apple fell to the ground due to the pull of gravity.
3. The country's economy is a matter of gravity.
4. He spoke with a sense of gravity about the future of the nation.
5. Gravity affects all objects in the universe.