To wail means to cry out loudly in grief, pain, or distress. It's more intense than ordinary crying: a wail is a long, high-pitched sound that comes from deep sadness or hurt. You might hear a young child wail after falling hard on the playground, or an ambulance siren wail as it rushes through traffic.

In stories and history, people wail at funerals or after terrible news, expressing sorrow too strong for quiet tears. The word captures both the sound and the feeling behind it: when someone wails, you can hear their anguish or despair in every note.

The word also describes similar sounds that aren't necessarily human. Wind can wail through bare tree branches on a cold night, creating an eerie, mournful sound. A cat might wail outside at night, and musicians sometimes make their instruments wail, especially in blues or rock music, where a guitar or harmonica mimics that crying, emotional sound.

As a noun, a wail is the sound itself: “We heard the wail of the wind” or “Her wail of disappointment echoed through the house.”