adagioPronunciation: /əˈdɑː(d)ʒɪəʊ/ MusicDefinition of adagio adverb & adjective (especially as a direction) in slow time. noun (plural adagios) a movement, passage, or composition marked to be performed adagio. Origin:Italian, from ad agio 'at ease'adagio in other Oxford dictionaries Definition of adagio in the US English dictionary