galloper

gallop +‎ -er

galloper (plural gallopers)

1. One who gallops.
   • a. 1898, Rudyard Kipling, "The Drums of the Fore and Aft"

     The lancers chafing in the right gorge had thrice dispatched their only subaltern as galloper to report on the progress of affairs.

2. An aide-de-camp.
   • “Lieutenant Nevill Josiah Aylmer Coghill, 24th Regiment”, in North East Medals‎:

     Lieutenant Coghill had been told to act as galloper to Colonel Glyn on the unfortunate reconnaissance made from Isandlwana Camp, on January 22, 1879

3. A racehorse.
   • 2009 January 25, Rod Nicholson, “Get ready for Hussler v Cat”, in Herald Sun‎:

     The Hussler's trainer, Ross McDonald, is confident Australia's champion galloper will win the clashes, despite Weekend Hussler never having competed over 1000m before.

4. A carousel or roundabout (especially in the plural)
5. (military) A carriage on which very small guns were formerly mounted, the gun resting on the shafts, without a limber.
6. (Australia) The Chinamanfish, a type of snapper