: a jump (as in figure skating or skiing) that consists of at least four but less than five revolutions
Last month Leaver announced that Boitano would not try the jump for which he is best known, the quadruple toe loop, at the Olympics. Never performed successfully in competition, the quad has become the slippery grail of skating. Jill Smolowe
: having or composed of four items or elements : quadruplesense 1
The F/A-18 flight-control system … is characterized by quad redundancy, which means that there are essentially four levels of sensing and actuation for each control surface.McGraw-Hill Yearbook Of Science And Technology
Quad skates are roller skates that have four wheels arranged in two rows, while inline skates have them in one line. Jenee Osterheldt
Domestic quad listening needs two additional loudspeakers over stereo, and two more amplifiers, plus the black box which allocates some of the sounds to the rear left/right, and others to the front left/right. George Steedman
: the greater extensor muscle of the front of the thigh that is divided into four parts : quadriceps—usually plural
"Usually after a heptathlon I can tell if I'm not going to do well jumping. My quads get tired." Jackie Joyner-KerseeDick Williams, Seattle manager, on shortstop Spike Owen's injured quads: "I never had any quads when I played." — Sports Illustrated