This is the 11135th most frequent German word.
secret
The German word for "secret" is "Geheimnis," which means something kept hidden or unknown from others.
'Geheimnis' refers to a mysterious fact or knowledge not commonly known, here related to an old castle.
Das Geheimnis der alten Burg wird immer faszinierender.
The secret of the old castle is becoming more fascinating.
'Geheime' describes something confidential or private, in this case, a recipe.
Hans behielt das geheime Rezept für die Torte für sich.
Hans kept the secret recipe for the cake to himself.
'Geheimen' indicates classified or sensitive information, pertaining to documents.