| Zirkus | circus |
| Zirrus | cirrus |
| zirka | approximate |
| Zirkel | compass pair of compasses circle |
| Zirkon | zircon |
| Arkus | arc |
| Markus | Mark Marlin Marlon |
| Diskus | discus |
| Fiskus | treasury |
| Zirkular | circular letter |
| Zirmet | hartwort |
| Zirpen | chirp |
| zirpen | chirp |
| Zirbel | Swiss stone pine arolla pine |
| Irkutsk | Irkutsk |
| Kirke | Circe |
| Wirken | legacy |
| wirken | work act operate take effect appear seem knit |
| Birke | birch |
| Dirk | topping lift |