acceleration of gravity

n. (Abbr. g)
The acceleration of freely falling bodies under the influence of terrestrial gravity, equal to approximately 9.81 meters (32 feet) per second per second.

Constant acceleration of a body falling freely under gravity, in a vacuum, or when air resistance is negligible. It varies slightly in different geographical locations as a result of differences in the distance from the centre of mass of the Earth. The standard accepted value, usually abbreviated as g, is 9.80 665 ms⁻¹ s⁻¹, or 32.17 feet s⁻¹ s⁻¹. Skydivers are sometimes said to be in free fall, but this is not strictly true, because their downward velocity is reduced by air resistance.