gravitational force

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun The weakest of the four fundamental forces of nature, being the attractive force that arises from gravitational interaction. Newton's law of gravity states that the gravitational force between two bodies is proportional to the product of their masses and inversely proportional to the square of the distance between them.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun physics a very long-range, but relatively weak fundamental force of attraction that acts between all particles that have mass; believed to be mediated by gravitons

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun (physics) the force of attraction between all masses in the universe; especially the attraction of the earth's mass for bodies near its surface