mariachiPronunciation: /ˌmarɪˈɑːtʃi/Definition of mariachi noun (plural mariachis) [as modifier] denoting a type of traditional Mexican folk music, performed by a small group of strolling musicians. a musician in a group performing mariachi music: a town where roving mariachis still appear on Saturday nights [as modifier]:a mariachi bandOrigin:from Mexican Spanish mariache, mariachi 'street singer'mariachi in other Oxford dictionaries Definition of mariachi in the US English dictionary