Definition of "Gravitation" :

noun: a figurative movement toward some attraction

"The gravitation of the middle class to the suburbs."

noun: movement downward resulting from gravitational attraction

"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

"The gravitation between two bodies is proportional to the product of their masses and inversely proportional to the square of the distance between them."