| Konspirationstheoretiker | conspiracy theorist |
| Konspirationstheoretikerin | conspiracy theorist |
| Konspirationstheorie | conspiracy theory |
| Operationsverstärker | op-amp |
| Informationstheorie | information theory |
| Sensationsreporter | paparazzo |
| Ionisationstechnik | Ionisation technique ionization technique |
| Populationsgenetik | population genetics |
| Verschwörungstheoretiker | conspiracy theorist |
| Konditionierer | conditioner |
| Konfessionsfreier | nonsectarian |
| Konspiration | conspiracy |
| Konversationslexikon | encyclopedia |
| Koalitionsrechner | coalition builder |
| Evolutionstheorie | theory of evolution |
| Ionisationseffekt | ionisation effect |
| Koalitionspartner | coalition partner |
| Optionsschreiber | grantor option writer writer |
| Reinkarnationstherapie | past life regression |
| Kunsthistoriker | art historian |