quad /kwɒd $ kwɑːd/ BrE AmE noun [countable]
[ Sense 1: Date: 1800-1900 ; Origin: quadrangle ]
[ Sense 2: Date: 1800-1900 ; Origin: quadruplet ]
[ Sense 3: Date: 1900-2000 ; Origin: quadriceps ]
1 . informal a square open area with buildings all around it, especially in a school or college
2 . informal a ↑ quadruplet
3 . quads [plural] informal ↑ quadriceps