somniloquy vs sleep talking

somniloquy and sleep talking both are nouns.

Word	Noun	Adjective	Verb	Adverb
somniloquy	Yes	No	No	No
sleep talking	Yes	No	No	No

As nouns, somniloquy and sleep talking are synonyms defined as:

Other synonyms of somniloquy include somniloquism.

somniloquy (noun)	sleep talking (noun)
uttering speech while asleep	uttering speech while asleep