Definition of: carrier

(kar′ē·ər) noun
1. One who or that which carries; hence, a person or company that undertakes to carry persons or goods for hire, as a railroad company, etc.; also, one who carries or delivers messages, letters, etc.
2. A carrier pigeon.
3. A conduit.
4. Chem. A material used as an intermediary or vehicle, as a catalytic agent acting to transfer an element between compounds.
5. Mech. A device or attachment that conveys, drives, moves, or supports something.
6. A ship for carrying aircraft.
7. Bacteriol. One who is immune to a disease but transmits it to others by carrying the bacteria in his body.
8. A carrier wave.
—common carrier A person or company that undertakes to carry persons or goods for pay when called to do so, whether by land, air, or water, and that is liable for all loss or damage during transportation except such losses as arise from natural causes.