Quadrangle in architecture, e.g., on a university campus
Quad, a dormitory room or suite housing four residents
Quad Cities, a region which includes the cities of Iowa cities of Bettendorf and Davenport and the Illinois cities of Moline, East Moline, and Rock Island

Games

Quad Damage, a Quake and Unreal Tournament power-up
Quad, a type of combined robotic enemy in the Nintendo Gamecube game Metroid Prime 2
Quad (more commonly Quads), four of a kind in poker
Quad, an Harkonnen attack vehicle from the computer game Dune 2
Quad cannon, an anti-air weapon in Command & Conquer: Generals

Music, theatre and film

Quad (play), by Samuel Beckett
Quad (music), a musical project by Gary Ramon
Quad Electroacoustics, a British manufacturer of electronic amplifiers, tuners and loudspeakers mainly for the high-end domestic market
Quadraphonic, or four-channel sound
Quad Toms, marching percussion instrument
Quad, a film poster in the United Kingdom typically measuring 30 x 40 inches
The Quads, the British new-wave band
John Callahan's Quads!, an animated series from Nelvana
Quad, a unit of computer storage measurement in the fictional Star Trek universe

Quadriceps, a muscle
Quadruped, a creature or mechanism which moves on four legs
Quad (energy), a unit of energy (short for quadrillion) defined as 1015 British thermal units (about 1.055 exajoule (EJ) or 1.055 × 1018 J)
Quadrilateral, a four sided figure in plane geometry
Quadratic, the second power in mathematics
Quadrangle (geography), a 7.5-minute topographic map produced by the United States Geological Survey, covering in greater detail one quarter of the area of a 15-minute map
QUaD, a telescope located at the South Pole that is designed to measure the cosmic microwave background radiation polarization

Quad, a derogatory term for a quadriplegic
Quadrangle Club, one of the ten eating clubs at Princeton University
Quad, a unique member of a small group of employees from a single organisation sharing a common experience

Quad, a boat configuration in rowing that contains 4 people, with 2 oars each, and no coxswain
Quad, a chairlift in skiing which carries four persons
Quad (figure skating), a figure skating jump with four revolutions
Quad skates, roller skates with two wheels on each of two axles
All-terrain vehicle

Quad-core
Quad precision, a number stored using 16 eight-bit bytes, which is four times the size of 4-byte single precision
Quad Electroacoustics, a British manufacturer of electronic amplifiers, tuners and loudspeakers mainly for the high-end domestic market
Quad, an abbreviation for a type of videotape recorder, especially 2" Quadruplex videotape, where there are four record heads on a spinning drum which move perpendicular to the direction of tape travel
Quad, telecommunication term referring to a cable with four conductors in a square formation used to form two balanced pairs
Star quad, a cable with four conductors in a square formation, in which opposite conductors are connected in parallel at both ends to form a single, magnetically-concentric balanced pair, in order to minimise magnetic induction
Quadraphonic, or four-channel sound
quad, abbreviation for Quadrupole ion trap
Em quad, in typography, a space that is as wide as the height of the font
- En quad, a space that is one half the width of an em quad
QUAD_(cipher), a stream cipher

Quadriga
Quadruple combination fire apparatus that features a pump, tank, hose and a full complement of ground ladders
Quad, a tandem bicycle with four seats
Quad, a muscle car with a four-barrel carburetor
Quad, the nickname of the Morris C8 artillery gun tractor
Quad (rocket), an autonomous rocket by Armadillo Aerospace
Quads refer to four exhaust pipes (usually grouped two on each end) of a vehicle

quad in French: Quad (homonymie)

quad in Italian: Quad

quad in Dutch: Quad