| Reaktor | reactor |
| Rektor | rector principal |
| Reaktion | reaction |
| reaktiv | reactive |
| Aktor | actuator |
| Faktor | factor merchant |
| Refraktor | refracting telescope refractor |
| Traktor | tractor |
| Hektor | Hector |
| Lektor | lector reader lecturer literary editor |
| Sektor | sector |
| Vektor | vector |
| Reaktant | reactant |
| Reaktionär | reactionary |
| reaktionär | reactionary |
| Realgar | realgar |
| Kreatur | creature wight |
| Reaktanz | reactance |
| Fraktur | fracture blackletter script |
| Redakteur | editor |