script vs libretto

script and libretto both are nouns.

Word	Noun	Adjective	Verb	Adverb
script	Yes	No	Yes	No
libretto	Yes	No	No	No

As nouns, libretto is a hyponym of script; that is, libretto is a word with a more specific, narrower meaning than script:

script: a written version of a play or other dramatic composition; used in preparing for a performance
libretto: the words of an opera or musical play

script (noun)	libretto (noun)
a written version of a play or other dramatic composition; used in preparing for a performance	the words of an opera or musical play
a particular orthography or writing system
something written by hand

script (verb)	libretto (verb)
write a script for