This is the 4617th most frequent German word.
stützen
"Stützen" means "to support" or "to prop up."
It conveys the meaning of physical support, specifically the column providing structural stability to the roof.
Die Säule stützt das Dach des Gebäudes.
The column supports the roof of the building.
Here, the word is used metaphorically to denote emotional or moral support, illustrating mutual assistance among friends.
In schwierigen Zeiten stützen Freunde einander.
In difficult times, friends support each other.
In this instance, 'stützen auf' means 'to base on,' indicating logical dependence or foundation of the theory on experimental evidence.