/ Dictionary / Index U untether: Meaning and Definition of Find definitions for: un•teth•er Pronunciation: (un-te'ur), [key] — v.t. to release from a tether: to untether a horse. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Unterwalden unthankful Related Content Daily Word Quiz: spectral Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language