soliloquy vs monologue

soliloquy and monologue both are nouns.

Word	Noun	Adjective	Verb	Adverb
soliloquy	Yes	No	No	No
monologue	Yes	No	No	No

As nouns, soliloquy and monologue are synonyms defined as:

soliloquy (noun)	monologue (noun)
speech you make to yourself	speech you make to yourself
a (usually long) dramatic speech intended to give the illusion of unspoken reflections	a (usually long) dramatic speech by a single actor
	a long utterance by one person (especially one that prevents others from participating in the conversation)