Carrier

[1] A real or imaginary particle responsible for the transport of electric charge in a material. In oxide ceramics, electrons hopping between ions, diffusing oxygen ions and mobile cations can also transport charge. See carriers.
[2] A device for conveying the drive of a face-plate of a lathe to a piece of work which is being turned between centers. It is clamped to the work and driven by a pin projecting from the face-plate.
[3] A frame for holding a negative in an enlarger or slides in a projector.
[4] Non-active material mixed with, and chemically identical to, a radioactive compound. Carrier is sometimes added to carrier-free material.
[5] A vehicle for communicating in formation, when the chosen medium itself cannot convey the information but can convey a carrier, on to which the information is impressed by modulation.
[6] In radio transmission, the output of the transmitter before it is modulated. See frequency modulation.
[7] The frequencies chosen for sending many signals simultaneously along a single communication channel by frequency-division multiplex.
[8] A thin substance that helps another substance to reach its goal. For example, a spray grease may have a carrier which transports the grease to its destination. Then the carrier dries up leaving the grease behind. See barge carriers, bicycle carrier, bulk carrier, carrier bearing, contract carrier, differential carrier, hub carrier, jet carrier, lng carrier, luggage carrier, ore-bulk-oil carrier, ore carrier, pinion carrier, planet carrier, product carrier, spare tire carrier