precaution

(noun) a precautionary measure warding off impending danger or damage or injury etc.. Synonyms: safeguard, 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) the trait of practicing caution in advance.

(noun) judiciousness in avoiding harm or danger. Synonyms: caution, care, forethought. Examples: "He exercised caution in opening the door." "He handled the vase with care."