| Karotinoid | carotenoid |
| Carotinoid | carotenoid |
| Karotin | carotene carotin |
| Actinoid | actinide actinoid |
| Kardioide | cardioid |
| Karolinen | Caroline Islands |
| Karolinger | Carolingian |
| Karzinom | carcinoma |
| Carotin | carotene |
| Komotini | Komotini |
| Martini | martini |
| Konoid | conoid |
| paranoid | paranoid |
| Parasitoid | parasitoid |
| Karaimin | Karaim |
| Karaitin | Karaite |
| Karborund | carborundum |
| Kardinale | cardinal numeral |
| Karerin | Carian |
| Kargland | barren |