| Ökoenergie | green energy green power |
| Bioenergie | bioenergy |
| Ökologie | ecology |
| Ökonomie | economy |
| Energie | energy |
| Synergie | synergy |
| Ökologin | ecologist |
| Tokologie | tocology |
| Ökologe | ecologist |
| Ökonometrie | econometrics |
| Ökonomin | economist |
| Konterbier | hair of the dog |
| Konvertit | convert |
| Könige | Kings |
| Konserve | preserve |
| Königin | queen |
| Hydroenergie | hydropower |
| Clownerie | tomfoolery |
| Energie- | energetic |
| Omanerin | Omani |