noun: a figurative movement toward some attraction
Example: "The gravitation of the middle class to the suburbs"
noun: movement downward resulting from gravitational attraction
Example: "Irrigation by gravitation rather than by pumps"
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
Example: "The gravitation between two bodies is proportional to the product of their masses and inversely proportional to the square of the distance between them"