| Geheimfach | secret compartment |
| Geheimzahl | PIN |
| Geheimbund | secret society |
| Geheimnis | secret |
| Geheimsprache | secret language |
| Geheimtipp | tip |
| geheim | secret confidential hidden |
| heimisch | indigenous native |
| heimlich | clandestine secret covert |
| unheimlich | scary uncanny weird |
| Lehrfach | subject |
| Nebenfach | minor |
| vereinfacht | schematic |
| Eisfach | freezer compartment ice-box |
| Gefach | labor union |
| Gefrierfach | freezing compartment |
| dreifach | triple threefold |
| einfach | simple easy simply single |
| mehrfach | multiple repeatedly |
| zehnfach | tenfold |