cav|al|ry «KAV uhl ree», noun, plural -ries.
1. Military. a) soldiers who fight on horseback; a branch of an army consisting of such troops (now mostly obsolete): »

At 19, he went to Mexico where he joined the Mexican Army cavalry for two years to perfect his horsemanship (Newsweek).

b) soldiers who fight from armored vehicles; a branch of an army in which supplies and soldiers are conveyed by motor vehicles. Animals are employed only occasionally. Abbr: Cav.
3. Obsolete. horsemanship
[< Middle French cavalerie < Italian cavalleria mounted militia; knighthood < cavaliere cavalier]

Useful english dictionary. 2012.