One that transports or conveys: baggage carriers; a message carrier. One, such as a person, business, or organization, that deals in the transport of passengers or goods. A mechanism or device by which something is conveyed or conducted. Medicine A person or an animal that shows no symptoms of a disease but harbors the infectious agent of that disease and is capable of transmitting it to others. 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. Electronics A carrier wave. Electronics A charge-carrying entity, especially an electron or a hole in a semiconductor. An aircraft carrier. An insurance or underwriting organization. A telecommunications company.