The definition of mano a mano is a Spanish expression that is defined as hand to hand and is used to refer to a face-to-face confrontation between two people.(noun)
See mano a mano in Webster's New World College Dictionary
Origin: Sp, lit., hand to hand
See mano a mano in American Heritage Dictionary 4
noun pl. ma·nos a ma·nos (mäˈnōs ä mäˈnōs)
Origin: : mano, hand
Origin: + a, to.