The gravitational force, or g-force, is a term in physics for describing the force of gravity or acceleration on an object.
In 2377, in a story narrated by Neelix to a group of children, Commander Chakotay was riding a turbolift when it plunged eleven decks at high speed. Until the descent stabilizers were reactivated, Chakotay was held captive by the g-forces to the ceiling of the turbolift cab. (VOY: "The Haunting of Deck Twelve")
In 3189, upon regaining consciousness from having time traveled through a wormhole, Sylvia Tilly expressed how her head felt like it was in a vice. To this, Jett Reno responded, "Tidal forces from the wormhole. Like g-forces but nastier. Must've knocked us all out." (DIS: "Far From Home")