Definitions of carrier:

• noun:   a rack attached to a vehicle; for carrying luggage or skis or the like
• noun:   a self-propelled wheeled vehicle designed specifically to carry something

  Example: "Refrigerated carriers have revolutionized the grocery business"

• noun:   a person or firm in the business of transporting people or goods or messages
• noun:   a person who has some pathogen to which he is immune but who can pass it on to others
• noun:   a boy who delivers newspapers
• noun:   someone whose employment involves carrying something

  Example: "The bonds were transmitted by carrier"

• noun:   an inactive substance that is a vehicle for a radioactive tracer of the same substance and that assists in its recovery after some chemical reaction
• noun:   a large warship that carries planes and has a long flat deck for take-offs and landings
• noun:   a radio wave that can be modulated in order to transmit a signal
• noun:   a man who delivers the mail
• name:  A surname (common: 1 in 16666 families; popularity rank in the U.S.: #1952)