the action of relieving someone's fears or removing their doubts, the action of restoring their confidence and making them more assured, or the state of being thus relieved or assured;
e.g. He offered his reassurance that everything would go as planned. She wanted reassurance that she was doing the right thing.
(noun)
a remark or statement that relieves someone's fears or removes their doubts;
e.g. They needed to hear a reassurance before continuing their task.