Quad as a word or prefix usually means 4. It may refer to:

Government

Quadrilateral Security Dialogue The Quad is a grouping of Australia, India, Japan, and the United States that is maintained by talks between member countries. The grouping follows the "Tsunami Core Group" and its "new type of diplomacy" developed in response to the 2004 2004 ...

, a strategic security dialogue between Australia, India, Japan, and the United States * Quadrilateral group, an informal group that includes the trade spokesmen of the United States, Japan, Canada, and the European Union *

Quad Cities The Quad Cities is a region of five cities (originally Tri-Cities, later four, see #History, History) in the U.S. states of Iowa and Illinois: Davenport, Iowa, Davenport and Bettendorf, Iowa, Bettendorf (the fifth to be included) in southeaster ...

, a group of five cities straddling the boundary between the U.S. states of Iowa and Illinois * The "Quad", the senior members of the

Cameron–Clegg coalition The Cameron–Clegg coalition was formed by David Cameron and Nick Clegg when Cameron was invited by Queen Elizabeth II to form a new government, following the resignation of Prime Minister Gordon Brown on 11 May 2010, after the general el ...

government in the United Kingdom from 2010 to 2015

Art and entertainment

* Matthias Quad (1557–1613), engraver and cartographer * ''Quad'' (film), 2015 * Quad (music), a musical project by Gary Ramon * ''Quad'' (play), by Samuel Beckett * ''The Quad'' (TV series), 2017 * Quad (arts centre), in Derby, United Kingdom * Quad Cinema, art house in New York City, New York * Quad (studio), a Japanese animation studio * Quadruple combination, the four books that comprise the canon of the LDS church

Business

* Quad (company), an American marketing solutions company * Quad Electroacoustics, a British manufacturer of audio equipment

Medicine and anatomy

Quadriplegic Tetraplegia, also known as quadriplegia, is defined as the dysfunction or loss of Motor control, motor and/or Sense, sensory function in the Cervical vertebrae, cervical area of the spinal cord. A loss of motor function can present as either weak ...

, a person paralyzed in all four limbs *

Quadriceps The quadriceps femoris muscle (, also called the quadriceps extensor, quadriceps or quads) is a large muscle group that includes the four prevailing muscles on the front of the thigh. It is the sole extensor muscle of the knee, forming a large ...

, a large leg muscle group * Quadruplets, four children from a multiple birth

Sports

* Quad (figure skating), a figure skating jump with four revolutions *

Quad scull A quadruple sculling boat, often simply called a quad and abbreviated as a 4x, is a racing shell used in the sport of competitive rowing. It is designed for four people who propel the boat by sculling with two oars, or "sculls", one in each h ...

, a boat configuration of four rowers * Quad skates, roller skates with two wheels on each of two axles * Quad, one of the divisions in

wheelchair tennis Wheelchair tennis is one of the forms of tennis Adaptive sport, adapted for wheelchair users. The size of the court, net height and rackets are the same, but there are two major differences from pedestrian tennis: athletes use specially designe ...

Quadruple-double In basketball, a double-double is a single-game performance in which a player accumulates ten or more in two of the following five statistical categories: point (basketball), points, rebound (basketball), rebounds, assist (basketball), assist ...

, a statistical accomplishment in basketball * Quadrennium, the 4-year training cycle between Olympic games

Transportation

* Quad bike or all-terrain vehicle, a vehicle that travels on low-pressure tires * Quad, a tandem bicycle with four seats *

Quadracycle A quadracycle (also spelled quadricycle) is a four-wheeled human-powered land vehicle. It is also referred to as a quadcycle, pedal car or four-wheeled bicycle amongst other terms. Quadracycles have been in use since 1853 and have grown int ...

, a four-wheeled human-powered land vehicle * Jeffery Quad, a four-wheel drive truck *

Quadcopter A quadcopter, also called quadrocopter, or quadrotor is a type of helicopter or multicopter that has four rotors. Although quadrotor helicopters and convertiplanes have long been flown experimentally, the configuration remained a curiosity ...

, a four-rotor helicopter * Quad, a

chairlift An elevated passenger ropeway, or chairlift, is a type of aerial lift, which consists of a continuously circulating steel wire rope loop strung between two end terminals and usually over intermediate towers. They are the primary on-hill tran ...

in skiing which carries four persons * Quad, or railroad speeder, a motorized vehicle used for maintenance on railroads * Quad (rocket), an autonomous rocket by Armadillo Aerospace

Technology

* QUAD (cipher), a stream cipher *

QUaD QUaD, an acronym for QUEST at DASI, was a ground-based cosmic microwave background (CMB) polarization experiment at the South Pole. QUEST (Q and U Extragalactic Sub-mm Telescope) was the original name attributed to the bolometer detector instrume ...

, a microwave telescope at the South Pole * Quad antenna, a directional antenna *

Quadraphonic sound Quadraphonic (or quadrophonic, also called quadrasonic or by the neologism quadio formed by analogy with "stereo"">portmanteau.html" ;"title="/nowiki>portmanteau">formed by analogy with "stereo" sound – equivalent to what is now called 4.0 s ...

, four-channel sound *

Quadruplex videotape 2-inch quadruplex videotape (also called 2" quad video tape or quadraplex) was the first practical and commercially successful analog recording video tape format. The format uses magnetic tape and was developed and released for the broadcast t ...

, video tape format * Quad Flat Package, a type of package for surface mounted integrated circuit * Star quad cable, four insulated conductors twisted together

Other uses

* Quad (unit), unit of energy, short for ''quadrillion'', 10¹⁵ BTU *

Quadrangle (architecture) In architecture, a quadrangle (or colloquially, a quad) is a space or a courtyard, usually rectangular (square or oblong) in plan, the sides of which are entirely or mainly occupied by parts of a large building (or several smaller buildings). Th ...

, a space or courtyard bordered by buildings * Quad (geography), a United States Geological Survey topographical map *

Quad (typography) In typography, a quad (originally ''wikt:quadrat#Etymology_2, quadrat'') was a metal spacer used in letterpress typesetting. The term was later adopted as the generic name for two common sizes of Space (punctuation), spaces in typography, regardles ...

, a spacer used in letterpress type *

Quadrilateral In Euclidean geometry, geometry a quadrilateral is a four-sided polygon, having four Edge (geometry), edges (sides) and four Vertex (geometry), corners (vertices). The word is derived from the Latin words ''quadri'', a variant of four, and ''l ...

, in geometry * Quad poster, a common UK size of

film poster A film poster is a poster used to promote and advertise a film primarily to persuade paying customers into a theater to see it. Studios often print several posters that vary in size and content for various domestic and international markets. The ...

Quadrat A quadrat is a frame used in ecology, geography, and biology to isolate a standard unit of area for study of the distribution of an item over a large area. Quadrats typically occupy an area of 0.25 m2 and are traditionally square, but modern quad ...

, in ecology, a small study area or a frame used to define it * Quadrupel, a Belgian beer * The Quad Casino (now The Linq), on the Las Vegas Strip * Four-of-a-kind in poker * Sako Quad, a Finnish bolt-action rifle * Morris C8, a WWII era artillery tractor