gravity

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. Physics The natural force of attraction exerted by a celestial body, such as Earth, upon objects at or near its surface, tending to draw them toward the center of the body.
2. n. Physics The natural force of attraction between any two massive bodies, which is directly proportional to the product of their masses and inversely proportional to the square of the distance between them.
3. n. Physics Gravitation.
4. n. Grave consequence; seriousness or importance: They are still quite unaware of the gravity of their problems.
5. n. Solemnity or dignity of manner.

Century Dictionary and Cyclopedia

1. Weight, as contradistinguished from mass; precisely, the downward acceleration of terrestrial bodies, due to the gravitation of the earth modified by the centrifugal force due to its rotation on its axis. The amount of this acceleration is about 385. 1 inches (978 centimeters) per second at the sea-level and the equator, while at the poles it is 387.1 inches. Gravity is a little less on mountains than at the sea-level, in the proportion of a diminution of one thousandth part at every two miles of elevation. There are also other slight variations of gravity, from which the figure of the geoid (which see) can be calculated. Generally speaking, gravity is in excess where the radius vector of the geoid is in excess of that of the mean spheroid. [The words gravity and gravitation have been more or less confounded; but the most careful writers use gravitation for the attracting force, and gravity for the terrestrial phenomenon of weight or downward acceleration which has for its two components the gravitation and the centrifugal force. The centrifugal force at the equator is 1/289.4 of gravity. It is everywhere exerted in the plane of the meridian at right angles to the direction of the celestial pole. The direction of gravitation in middle latitudes is inclined about 11'.5 to the radius of the earth.
2. Solemnity of deportment or character; sedateness of demeanor; seriousness.
3. Importance; significance; dignity.
4. In acoustics, the state of being low in pitch: opposed to acuteness.

Wiktionary

1. n. Resultant force on Earth's surface, of the attraction by the Earth's masses, and the centrifugal pseudo-force caused by the Earth's rotation.
2. n. Gravitation, universal force exercised by two bodies onto each other (In casual discussion, gravity and gravitation are often used interchangeably).
3. n. The state or condition of having weight; weight; heaviness.
4. n. Specific gravity.
5. n. The state or condition of being grave (graveness).

GNU Webster's 1913

1. n. The state of having weight; beaviness.
2. n. Sobriety of character or demeanor.
3. n. Importance, significance, dignity, etc; hence, seriousness; enormity.
4. n. (Physics) The tendency of a mass of matter toward a center of attraction; esp., the tendency of a body toward the center of the earth; terrestrial gravitation.
5. n. (Mus.) Lowness of tone; -- opposed to acuteness.

WordNet 3.0

1. n. a solemn and dignified feeling
2. n. a manner that is serious and solemn
3. n. (physics) the force of attraction between all masses in the universe; especially the attraction of the earth's mass for bodies near its surface