Un-nerves is a word that means to calm or soothe someone's fears or anxiety. The opposite of un-nerves would be to cause nervousness or anxiety. In other words, antonyms for un-nerves would include words like tense, anxious, uneasy, apprehensive, worried, nervous, and agitated. These words all suggest a feeling of discomfort or unease, which is the opposite of what un-nerves tries to accomplish. When we un-nerves someone, we aim to relieve their stress and put them at ease. Conversely, when we fail to un-nerves them, we may cause further distress or anxiety. Therefore, it's crucial to choose the right words to un-nerves someone effectively.