Sigh

A sigh is an audible/bearable exhalation of air arising from tiredness or emotion, usually sadness, which itself could be stemming from feelings of sadness or futility.

This is the definition of sigh from Wikipedia which exactly how i felt when i sighed right now, it seems funny cause there are human interactions that can express our feelings whether it's a smile or a sigh and no matter who does it, it gives the same feeling.

**sigh**