Perhaps you should try some spelling variations:
passiveen » passiveand, passively, passiver
passiven » passion
passiverer » passiverwerb, passiver, passagerer
passieren » passiert
passivieren » passivierende, passivierung, passagieren

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: (passive OR ((passiveen OR passiven) OR ((passiverer OR passieren) OR passivieren))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(passive or ((passiveen OR passiven) or ((passiverer or passieren) or passivieren)))".
• Adding a wildcard symbol may retrieve word variants: (passive or ((passiveen OR passiven) or ((passiverer or passieren) or passivieren)))*.