language vs soliloquy

language and soliloquy both are nouns.

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

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

language (noun)	soliloquy (noun)
the mental faculty or power of vocal communication	speech you make to yourself
the cognitive processes involved in producing and understanding linguistic communication	a (usually long) dramatic speech intended to give the illusion of unspoken reflections
a systematic means of communicating by the use of sounds or conventional symbols
(language) communication by word of mouth
the text of a popular song or musical-comedy number
a system of words used to name things in a particular discipline