A sigh is a long, deep breath that shows you're feeling relieved or frustrated.
When we're feeling stressed or upset, we often let out a big sigh. You might hear someone sigh when they're stuck in a traffic jam, or when they've been dealing with a difficult problem for too long. You can even sigh just because you're happy to be sitting down after a long walk! It's a natural sound that means "I'm feeling overwhelmed" or "I'm really relieved now". Some people might say "I was holding my breath until this happened", but what they mean is they were so tense or worried, and when it finally got resolved, they let out a big sigh to show their relief.
(intransitive) To inhale a larger quantity of air than usual, and immediately expel it; to make a deep single audible respiration, especially as the result or involuntary expression of fatigue, exhaustion, grief, sorrow, frustration, or the like.
Example: When she saw it wasn't damaged, she sighed with relief.
