cavalry

noun, plural cav·al·ries.

1. Military.
   1. the part of a military force composed of troops that serve on horseback.
   2. mounted soldiers collectively.
   3. the motorized, armored units of a military force organized for maximum mobility.
2. horsemen, horses, etc., collectively.

noun plural -ries

1. (esp formerly) the part of an army composed of mounted troops
2. the armoured element of a modern army
3. (as modifier)a cavalry unit; a cavalry charge

n.

1540s, from Middle French cavalerie (16c.), from Italian cavalleria “mounted militia,” from cavaliere (see cavalier (n.)). An Old English word for it was horshere.