| Knopfloch | buttonhole |
| Kopf hoch | cheer up chin up |
| Kopftuch | headscarf kerchief head-kerchief |
| kopflos | headless |
| Knöterich | knotweed |
| Knoblauch | garlic |
| Knopf | button knob |
| knöpfen | button |
| Klopfholz | mallet |
| Kopf hoch! | cheer up |
| Kopfweh | headache |
| Kropfmilch | crop milk |
| Kopflaus | head louse |
| Pflock | peg stake |
| Bohrloch | borehole drill hole |
| Moloch | Moloch |
| Ozonloch | hole in the ozone layer ozone hole |
| Knobelei | brainteaser |
| Knorpelfisch | cartilaginous fish |
| Knossos | Knossos |