Don't leave unescorted from stable (6)
I believe the answer is:
secure
'stable' is the definition.
(thesaurus)
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for secure that I've seen before include "Free from danger and financially sound" , "Obtain - safe" , "lock" , "Stable" , "Safe and unthreatened" .)