| Primfaktor | prime factor |
| Formfaktor | form factor |
| Biofaktor | biofactor |
| Primfakultät | primorial |
| Primat | primate primacy |
| primär | primary |
| Krimtatar | Crimean Tatar |
| Faktor | factor merchant |
| Klirrfaktor | distortion factor |
| Störfaktor | disruptive element |
| Reaktor | reactor |
| Refraktor | refracting telescope refractor |
| Traktor | tractor |
| Prospektor | prospector |
| Projektor | projector |
| Protektor | protector |
| Prädiktor | predictor |
| Animator | animator |
| Prädator | predator |
| Prätor | praetor |