1: one that carries :bearer, messenger 2 a: an individual or organization engaged in transporting passengers or goods for hire b: a transportation line carrying mail between post offices c: a postal employee who delivers or collects mail d: one that delivers newspapers e: an entity (as a hole or an electron) capable of carrying an electric charge 3 a: a container for carrying b: a device or machine that carries :conveyor 4:aircraft carrier 5 a: a bearer and transmitter of a causative agent of an infectious disease; especially: one who carries the causative agent of a disease systemically but is asymptomatic or immune to it b: an individual (as one heterozygous for a recessive trait) having a specified gene that is not expressed or only weakly expressed in its phenotype 6 a: a usually inactive accessory substance :vehicle<a carrier for a drug or an insecticide>b: a substance (as a catalyst) by whose agency some element or group is transferred from one compound to another 7 a: an electromagnetic wave or alternating current whose modulations are used as communications signals (as in radio, telephonic, or telegraphic transmissions) b: a telecommunication company 8: an organization acting as an insurer