Noun

1. A deep and prolonged audible inspiration or respiration of air, as when fatigued, frustrated, or grieved; the act of sighing.
2. Figuratively, a manifestation of grief; a lament.
3. (cockney slang) A person with boredom

Verb

1. 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.
2. Hence, to lament; to grieve.
3. To make a sound like sighing.
4. To exhale (the breath) in sighs.
5. To utter sighs over; to lament or mourn over.
6. To express by sighs; to utter in or with sighs.
7. To express frustration.