a precautionary measure warding off impending danger or damage or injury etc.; "he put an ice pack on the injury as a precaution"; "an insurance policy is a good safeguard"; "we let our guard down"
a certain degree of unwillingness; "a reluctance to commit himself"; "his hesitancy revealed his basic indisposition"; "after some hesitation he agreed"
(physics) opposition to magnetic flux (analogous to electric resistance)