| Koronarvenensinus | coronary sinus |
| Koronararterie | coronary artery |
| Coronavirus | coronavirus |
| Kronprinzessin | crown princess |
| Koversinus | coversed sine |
| Koralleninsel | coral island |
| Koranismus | Quranism |
| Koreanerin | Korean |
| Kornkreis | crop circle |
| körnerfressend | granivorous seed-eating |
| Konsonantismus | consonantism |
| Kopenhagenerin | Copenhagener |
| Konsensus | consensus |
| Korallenfisch | butterfly fish |
| Korbmacherin | basketmaker |
| Korbwaren | wickerwork |
| Kornkrebs | wheat weevil |
| Kornrasterung | stipple |
| Korrespondentin | correspondent |
| Körperkreislauf | systemic circulation |