cav·al·ry 
/ˈkævəlri/ noun
/ˈkævəlri/ noun : the part of an army that in the past had soldiers who rode horses and that now has soldiers who ride in vehicles or helicopters [noncount] ▪ Cavalry is used to perform reconnaissance. [plural] ▪ The cavalry were brought in to support the mission. — often used before another noun ▪ cavalry forces/officers/troops — compare infantry
