It is the hypothetical source of/evidence for its existence is provided by: Latin loqui "to speak;" Old Irish ad-tluch- "to thank," to-tluch- "to ask;" Old Church Slavonic tloko "interpretation, explanation."
It is the hypothetical source of/evidence for its existence is provided by: Sanskrit svapnah, Avestan kvafna-, Greek hypnos, Latin somnus, Lithuanian sapnas, Old Church Slavonic sunu, Old Irish suan, Welsh hun "sleep;" Latin sopor "a deep sleep;" Old English swefn, Old Norse svefn "a dream."
<a href="https://www.etymonline.com/word/somniloquy">Etymology of somniloquy by etymonline</a>
Harper, D. (n.d.). Etymology of somniloquy. Online Etymology Dictionary. Retrieved $(datetime), from https://www.etymonline.com/word/somniloquy