1. a large amount or quantity of something
2. a large number of people or things grouped together
3. the amount of matter in an object
Usage: physics

1. involving or affecting large numbers of people

1. to gather together in large numbers

Examples

• A mass of clouds covered the sky.
• The protesters gathered in a large mass outside the building.
• Scientists measure the mass of objects in kilograms.
• The family attended Sunday mass at the local church.
• The company launched a mass marketing campaign.
• Crowds began to mass in the town square.
• She had a mass of curly hair.
• The mass media covered the story extensively.