sense of relief; feeling of relief
A straightforward noun for the emotion of relief, often used when a worry or tension is resolved.
Now that the exam is over, I'm filled with a sense of relief.
I felt relief at the phone call telling me they were safe.
Compound of 安堵 (relief, from 安 'peace' and 堵 'fence, barrier', originally meaning to be at ease within one's domain) and 感 (feeling, sensation).