| Quadratzahl | square number |
| Quadratfuß | square foot |
| Quadrat- | square |
| Quadrat | square |
| Quadratmeile | square mile |
| Quadratum | quadrate bone |
| Quadratur | quadrature |
| Quartal | quarter |
| quadratisch | quadratic square |
| Quartil | quartile |
| Quadrant | quadrant |
| Quadratestadt | City of Squares |
| Quadratmeter | square meter square metre |
| Quadratschädel | square head block |
| Quadratwurzel | square root |
| Quadriga | quadriga |
| Quadrizeps | quadriceps |
| Quarantäne | quarantine |
| Quartär | Quaternary |
| Quarzuhr | quartz watch quartz clock |