1. the earth and all the people and things on it
2. a particular region, country, or area of human activity
3. human society and civilization

Examples

• She traveled around the world in 80 days.
• The business world can be very competitive.
• He wants to make the world a better place.
• Welcome to the world of professional sports.
• The ancient world had many great civilizations.
• The art world was shocked by the discovery.
• World peace remains an important goal.
• She felt like she was in her own little world.