- (rather informal)formal quadrangle
an open square area that has buildings all around it, especially in a school or college 四方院子（四周有建筑的开放场地，常见于校园） Her office window overlooks the quad. 从她办公室的窗户可以俯瞰这个院落。
- quadruplet
one of four children born at the same time to the same mother 四胞胎之一