carrier pigeon

one of a breed of domestic pigeons having a large wattle around the base of the beak.

a homing pigeon trained to carry messages.

Origin of carrier pigeon

First recorded in 1640–50

The sight kept the three men dumb and motionless, 356 for they instantly divined that the bird was a carrier-pigeon.

The Shadow of the Czar |John R. Carling
Thus there was the less danger that the carrier-pigeon would be noticed.

The Golden Silence |C. N. Williamson and A. M. Williamson
A breathless silence lasted while Augustus perused the message taken from the neck of the carrier-pigeon.

Catholic World, Vol. XI, April 1870-September 1870 |Various
Carrier-Pigeon, a swindler, one who formerly used to cheat lottery-office keepers.

The Slang Dictionary |John Camden Hotten

It is not by instinct, but by sight, that the carrier-pigeon guides its course.

Harper's Young People, January 6, 1880 |Various

carrier pigeon

any homing pigeon, esp one used for carrying messages