Protects, watches over (6)
I believe the answer is:
guards
This clue is a double definition.
'protects' is the first definition.
(guarding is a kind of protecting)
'watches over' is the second definition.
(guarding is a kind of watching over)
(Other definitions for guards that I've seen before include "Defends" , "Protection" , "They keep watch" , "troops" , "Keeps watch" .)