sigh
Pronunciation: /sʌɪ/
verb
- emit a long, deep audible breath expressing sadness, relief, tiredness, or similar: Harry sank into a chair and sighed with relief
- (of the wind or something through which the wind blows) make a sound resembling a sigh: a breeze made the treetops sigh
- (sigh for) literary feel a deep yearning for (someone or something lost, unattainable, or distant): he sighed for days gone by
noun
- a long, deep audible exhalation expressing sadness, relief, tiredness, or similar: she let out a long sigh of despair figurative the councils heaved a sigh of relief when they saved over £6m between them
- a gentle sound resembling a sigh, especially one made by the wind: except for the sigh of the wind, it was very quiet

Origin:
Middle English (as a verb): probably a back-formation from sighte, past tense of siche, sike, from Old English sīcan