Laughter (noun)

1. The action or sound of laughing.
2. A cause or source of amusement or mirth.

Origin:

Middle english: from old norse hlæja, of germanic origin; related to dutch lach and german lachen.

Examples:

1. The children's laughter filled the room.
2. He couldn't help but join in the laughter.
3. The comedian's jokes brought a lot of laughter from the crowd.
4. She tried to stifle her laughter so as not to wake the baby.
5. The laughter died down as the group settled down to discuss business.