soliloquy vs actor's line

soliloquy and actor's line both are nouns.

Word	Noun	Adjective	Verb	Adverb
soliloquy	Yes	No	No	No
actor's line	Yes	No	No	No

As nouns, actor's line is a hypernym of soliloquy; that is, actor's line is a word with a broader meaning than soliloquy:

soliloquy: a (usually long) dramatic speech intended to give the illusion of unspoken reflections
actor's line: words making up the dialogue of a play

Other hypernyms of soliloquy include speech, words.

soliloquy (noun)	actor's line (noun)
speech you make to yourself	words making up the dialogue of a play
a (usually long) dramatic speech intended to give the illusion of unspoken reflections