| zirkumbinär | circumbinary |
| zirkumpolar | circumpolar |
| Zirkular | circular letter |
| Zirkumfix | circumfix |
| Zirkumzision | circumcision |
| Zirkumflex | circumflex |
| zirkadian | circadian |
| Zierkürbis | decorative gourd |
| nicht-binär | non-binary |
| nichtbinär | non-binary |
| Zirkulieren | circulation |
| zirkulieren | circulate |
| zirka | approximate |
| Zirkon | zircon |
| Zirkonium | zirconium |
| Zirkulation | circulation |
| Zirkus | circus |
| Birkenrinde | birchbark |
| Wirkung | effect impact |
| Arkussinus | arcsine |