| kostbar | precious valuable |
| Kostbarkeit | preciousness prize |
| knetbar | malleable |
| lösbar | soluble |
| Kosak | Cossack |
| Kosovare | Kosovan |
| Kosrae | Kosrae Kusaie |
| Kost | diet fare meal |
| Kosten | cost charges expenses fees damage |
| kosten | cost take get a taste of taste try enjoy |
| Kostenart | cost element |
| Kostüm | suit costume fancy dress |
| koscher | kosher kasher |
| Ostler | Oriental |
| Ostmark | ostmark |
| Ostrau | Ostrava |
| Aosta | Aosta |
| Kloster | monastery convent |
| Poster | poster |
| Obstbau | fruit-growing orcharding pomiculture |