All articles starting with G
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Gear
A gear, also called a gear wheel or cog wheel, is a toothed machine element that meshes with another to transmit rotation and torque between shafts.
Gear hobbing
Gear hobbing is a continuous gear-cutting process in which a worm-shaped cutter, the hob, and a gear blank rotate in sync, dominating production of external spur and helical gears.
Gear oil
Gear oil is a lubricant formulated for gear sets like manual transmissions and differentials, distinguished from engine oil by extreme-pressure additives and SAE J306 viscosity grades.
Gear pitting
Gear pitting is a rolling contact fatigue failure of gear tooth flanks in which cyclic contact stresses break small pieces of material out of the surface, leaving pits.
Gear pump
A gear pump is a positive displacement pump that carries fluid between meshing gear teeth and a close-fitting housing, coming in external and internal designs and moving a fixed volume per revolution.
Gear ratio
A gear ratio is the ratio of the input angular speed of a gear train to its output angular speed, trading speed against torque in any gearbox or transmission.
Gear stick
The gear stick, also called a gear lever or stick shift, is the hand-operated lever inside a vehicle that the driver moves to select gears in the transmission.
Gear strength rating
A gear strength rating is a calculated measure of how much load a gear tooth can carry, based on standardized methods such as ISO 6336 and ANSI/AGMA 2101.
Gear test rig
A gear test rig is a laboratory machine that runs gear pairs under controlled load, speed, temperature, and lubrication to measure wear, friction, efficiency, and failure modes.
Gear tooth thickness measurement
Gear tooth thickness measurement is the metrology practice of determining a gear tooth's thickness at or near the pitch circle, typically by chordal, span, or over-pins methods.
Gear train
A gear train is a set of meshing gears that transmit torque or power between shafts, changing speed, torque, or direction; they appear in vehicle transmissions, robots, and clocks.
Gearbox
A gearbox is a mechanical assembly of gears that transfers rotational power between shafts, changing speed and torque through a gear ratio, as in vehicles and wind turbines.
Gearbox Software
Gearbox Software, Frisco, Texas studio founded February 1999 by Randy Pitchford and veterans; creator of Borderlands (60M+ copies), Brothers in Arms, Duke Nukem Forever; Embracer-owned 2021–2024, then sold to Take-Two for $460 million; Borderlands 4 launched September 2025.
Geared steam locomotive
A geared steam locomotive sends cylinder power to its wheels through a line shaft and reduction gears instead of drive rods, developed in America for logging and mining.
Gearing-class destroyer
Gearing-class destroyer: US Navy class of 98 WWII destroyers (DD 710 class), a 14-foot lengthened Allen M. Sumner hull with greater fuel capacity; FRAM-modernized, Cold War service, two preserved.
Gearless mill drive
A gearless mill drive (GMD), or ring motor, is an electric drive for large grinding mills where the mill shell itself acts as the motor rotor.
Gearóid Ó Cairealláin
Gearóid Ó Cairealláin (1957–2024), Belfast Irish-language activist, journalist, and playwright; founded Lá, Cultúrlann McAdam Ó Fiaich, Raidió Fáilte, Aisling Ghéar, and Coláiste Feirste; Conradh na Gaeilge president 1995–1998; father of Kneecap's Móglaí Bap.
Gears 5
Gears 5, also known as Gears of War 5, is a third-person cover shooter from The Coalition released in 2019 for Xbox One and PC, the fifth main Gears of War game.
Gears of War
Gears of War is a third-person cover-based shooter franchise set on Sera, created by Epic Games in 2006 and now developed by The Coalition under Xbox. Nine entries from the 2006 original to E-Day (2026); known for cover combat, Horde mode, and Unreal Engine.
Gears of War (video game)
Gears of War is Epic Games' 2006 Xbox 360 third-person shooter, also called GoW 1, following Marcus Fenix and Delta Squad against the Locust Horde on Sera. It popularized one-button cover shooting, active reload, and the chainsaw Lancer, and received two remasters.
Gears of War 2
Gears of War 2 (Gears 2) is Epic Games' 2008 Xbox 360 third-person cover shooter sequel, published by Microsoft; it introduced Horde mode (five players, 50 waves), chainsaw duels, and scored 93 on Metacritic.
Gears of War 3
Gears of War 3 is Epic Games' 2011 Xbox 360 third-person shooter concluding the original trilogy, with four-player campaign co-op, Horde 2.0, the new Beast mode, and a Metacritic score of 91.
Gears of War 4
Gears of War 4 (Gears 4): 2016 third-person cover shooter by The Coalition for Xbox One and Windows 10, starring JD Fenix, Kait, and Del against the Swarm, with Horde 3.0 and cross-play.
Gears of War: E-Day
Gears of War: E-Day is The Coalition's Unreal Engine 5 prequel released October 6, 2026 on Xbox Series X|S, PC and Steam, following young Marcus Fenix and Dom Santiago on Emergence Day, with Bravo Squad co-op, Horde Siege, and an 87 Metacritic rating.
Gears of War: Judgment
Gears of War: Judgment (Xbox 360, March 19, 2013), People Can Fly/Epic prequel about Kilo Squad's court-martial after Emergence Day; Declassified missions, star ratings, Aftermath, and the OverRun class-based multiplayer mode.
Geastrales
Geastrales (earth-stars) is an order of gasteroid basidiomycete fungi in subclass Phallomycetidae, family Geastraceae, genus Geastrum with 140 species; star-shaped spore-sac fruiting bodies, statismospores, worldwide litter decomposers.
Geastrum
Geastrum (earthstars) is a genus of Geastraceae fungi whose star-shaped fruiting bodies open into rays around a spore sac. Molecular phylogenies since 2014 replaced morphology-only classifications and revealed many hidden species, including within G. triplex.
Geastrum quadrifidum
Geastrum quadrifidum, the rayed earthstar, is a fornicate Geastraceae fungus described by Persoon in 1794, with 4-5 non-hygroscopic rays lifting a stalked, hoary spore case with a conical peristome; found in coniferous woodland across Europe and the Americas.
Geastrum triplex
Geastrum triplex, the collared earthstar, is a saprobic Geastraceae fungus on all continents except Antarctica, the largest Geastrum, with 4-8 rays, a saucer collar, and rain-puff spore dispersal.
Geats
The Geats (Old English Geatas, Old Norse gautar, Swedish gotar) were a North Germanic people of southern Scandinavia, the tribe of Beowulf; their homeland is placed in Gotaland or, per Graslund, Gotland, and they were later absorbed by the Swedes.