| Zykloide | cycloid |
| Zyklone | cyclone |
| Epizykloide | epicycloid |
| Zyklon | cyclone |
| Zyklop | cyclops |
| Zissoide | cissoid |
| Ankleide | closet |
| Umkleide | cabin changing room locker room |
| Zyklostome | cyclostome |
| Zyklotron | cyclotron |
| Zyklus | cycle |
| zyklisch | cyclic |
| Kyklop | cyclops |
| Kykladen | Cyclades |
| Ekloge | eclogue |
| Kloake | sewage system cloaca |
| Kloppe | a kind of |
| Myoklonie | myoclonia |
| Kolloid | colloid |
| Alkaloid | alkaloid |