| Kooptation | co-optation co-option |
| Kooperation | cooperation co-operation |
| Adaptation | adaptation |
| Koadaptation | coadaptation |
| Dotation | endowment |
| Kavitation | cavitation |
| Kommutation | substitution test |
| Konnotation | connotation |
| Notation | musical notation |
| Rotation | rotation |
| Votation | voting |
| Koedukation | coeducation |
| Kollation | collating collation |
| Komparation | comparison |
| Kopulation | copulation |
| Kooperative | cooperative |
| kooperativ | cooperative |
| Koordination | coordination |
| kooptieren | co-opt coopt |
| Koptin | Copt |