| Klothoide | clothoid |
| Klotho | Clotho |
| Kathode | cathode |
| Kathole | papist |
| Methode | method way |
| Kardioide | cardioid |
| Kolloid | colloid |
| Konoid | conoid |
| Zentroide | centroid |
| Astroide | astroid |
| Plutoid | plutoid |
| Klobrille | toilet seat |
| Klobürste | toilet brush |
| Klopfholz | mallet |
| Zykloide | cycloid |
| Kloake | sewage system cloaca |
| Klopapier | loo paper toilet paper |
| Kloppe | a kind of |
| Klotz | block |
| Klöten | ball bollock testicle |