Bone bootlick on—to cultivate the favor of.
Boots and Saddles—trumpet call.
Bootlick—to flatter.
Brig—guard-house.
Bow-legs—cavalrymen.
Buck-private—a term sometimes used in referring to a private.
Bucking for Orderly—giving clothing and accoutrements extra cleaning so as to compete for orderly.
Bunkie—a soldier who shares the shelter of a comrade.
Bust—to reduce a non-commissioned officer to the grade of a private.
Butcher—the company barber.