This is the 1982nd most frequent German word.
geheime
"Geheime" means "secret" in English.
Here, "geheimes" is used as an adjective to describe a "Rezept" (recipe), indicating something confidential or not commonly known.
Das ist ein geheimes Rezept meiner Großmutter.
This is a secret recipe from my grandmother.
In this sentence, "geheime" modifies "Versteck" (hideout), suggesting it is concealed or hidden from others.
Wir entdeckten das geheime Versteck im Wald.
We discovered the secret hideout in the forest.
Here, "geheimes" is applied to "Projekt" (project), implying that the project is intended to be kept undisclosed or confidential.