| zweifelsfrei | doubtless |
| Zweifelsfall | case of doubt |
| zweifelsohne | undoubtedly unquestionably |
| Zweifeln | dubitation |
| zweifeln | doubt |
| Zweifüßer | biped |
| Zweifüßerin | biped |
| Zweifüßler | biped |
| zweifelnd | doubtful |
| Zweifel | doubt |
| zweckfrei | pure purposeless |
| zweierlei | double |
| zweifelhaft | doubtful dubious |
| zweifellos | undoubtedly no doubt doubtless doubtlessly certainly indubitable |
| Teufelskreis | vicious circle |
| zinsfrei | interest-free |
| werbefrei | ad-free advertising-free commercial-free |
| Zeidlerei | beekeeping |
| Zweibeiner | biped |
| Zweibeinerin | biped |