safeguard

(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."

(noun) a document or escort providing safe passage through a region especially in time of war. Synonyms: safe-conduct.

(verb) make safe.

(verb) escort safely.