To feel or express sorrow or grief over a loss, especially the death of someone.
She mourned the loss of her beloved grandmother for many months.
To show the conventional or customary signs of grief for a death, such as wearing black clothing.
The entire community mourned by wearing black armbands for a week.
To feel or express sadness, regret, or distress over the loss, absence, or decline of something non-human or abstract (such as an opportunity, tradition, or place).
Environmentalists mourn the destruction of ancient forests around the world.