| Zweiersystem | binary numeral system |
| Zehnersystem | decimal |
| Untersystem | sub-system |
| Zwanzigersystem | vigesimal system |
| Leitsystem | distributed control system |
| Zahlensystem | number system |
| Zeichensystem | sign system |
| Zweiersofa | love seat |
| Zweifüßer | biped |
| Zweifüßler | biped |
| zweierlei | double |
| zweitbeste | second best |
| Leierkasten | barrel organ |
| Sechsersystem | senary |
| Abwassersystem | sewage system sewerage wastewater system |
| Binärsystem | binary system |
| Dateisystem | file system |
| Notensystem | stave |
| Wahlsystem | voting system |
| Exosystem | exosystem |