/ Dictionary / Index U unmyelinated: Meaning and Definition of Find definitions for: un•my•e•li•nat•ed Pronunciation: (un-mī'u-lu-nā"tid), [key] — adj. Anat. pertaining to nerve fibers that are not covered with a myelin sheath. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: unmyelinated (Thesaurus) unmuzzle unnail Related Content Daily Word Quiz: neologism Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language