| Optokoppler | optoisolator |
| Koppler | coupling |
| Optiker | optician |
| Fotokopierer | photocopier |
| Fotokopie | photocopy |
| apokopiert | apocopate |
| Apokope | apocope |
| Stopper | stop |
| Autostopper | hitch-hiker |
| Kuppler | matchmaker |
| Präkompiler | precompiler |
| Helikopter | helicopter |
| Optode | optode |
| Optographie | optography |
| Optometrie | optometry |
| optional | optional |
| Photokopie | photocopy |
| Tokelauer | Tokelauan |
| Autokarpie | autocarpy |
| Autokralle | wheel clamp |