somniloquy

Derived Formssomniloquist, nounsomniloquous, adjective

Word Origin for somniloquy

C19: from Latin somnus sleep + loqui to speak; compare soliloquy
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for somniloquy
n.

talking in one's sleep, 1847, from somni-, "sleep" + -loquy, from Latin loqui "to speak" (see locution). Related: Somniloquence (1814); somniloquent (1804, Coleridge); somniloquist; somniloquous; somniloquize.

Online Etymology Dictionary, © 2010 Douglas Harper

somniloquy in Medicine

somniloquy

[sŏm-nĭlə-kwē]
n.
  1. The act or habit of talking in one's sleep.
Related formssom•nilo•quist n.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.