LIBRETTO Meaning of LIBRETTO in English [li.bret.to] n, pl -tos or -ti [It, dim. of libro book, fr. L libr-, liber] (1742) 1: the text of a work (as an opera) for the musical theater 2: the book containing a libretto Merriam-Webster English vocab. Английский словарь Merriam Webster. 2012