1. people who actively support or promote something
2. additional doses of vaccine given to maintain immunity
Usage: medical
3. devices that increase power, signal strength, or effectiveness
Usage: technical

Examples

• The school’s boosters raised money for new uniforms.
• Local business boosters promoted the downtown festival.
• Children need boosters for certain vaccines before starting school.
• The doctor recommended getting flu boosters annually.
• Cell phone boosters improve signal strength in rural areas.
• The rocket’s boosters separated after launch.
• WiFi boosters extend internet coverage throughout the house.