1. One that transports or conveys: baggage carriers; a message carrier.

2. One, such as a person, business, or organization, that deals in the transport of passengers or goods.

3. A mechanism or device by which something is conveyed or conducted.

4. Medicine A person or animal that shows no symptoms of a disease but harbors the infectious agent of that disease and is capable of transmitting it to others.

5. Genetics An individual that carries one gene for a particular recessive trait. A carrier does not express the trait but, when mated with another carrier, can produce offspring that do.

6. Physics A boson, especially a gauge boson, that conveys a force or mediates an interaction between subatomic particles.

7. Electronics

8. An aircraft carrier.

9. An insurance or underwriting organization.

10. A telecommunications company.