safeguard
1. [ verb ] make safe
Related terms: protect precaution
2. [ noun ] a precautionary measure warding off impending danger or damage or injury etc.
Synonyms: precaution guard
Examples:

"he put an ice pack on the injury as a precaution" "an insurance policy is a good safeguard" "we let our guard down"

Related terms: measure protection security
3. [ noun ] a document or escort providing safe passage through a region especially in time of war
Synonyms: safe-conduct
Related terms: pass
4. [ verb ] escort safely
Related terms: escort safe-conduct