Libretto 601 Words You Need to Know
/lɪˈbret.əʊ/ (noun)
Definition
the text or script of an opera or musical, words of opera, stanza, lines, verse
Example
A libretto is the text used in, or intended for, an extended musical work such as an opera, operetta, masque, oratorio, cantata or musical. The term libretto is also sometimes used to refer to the text of major liturgical works, such as the Mass, requiem and sacred cantata, or the story line of a ballet.
Source: https://en.wikipedia.org/
Parts of speech
Noun: librettist