/ Dictionary / Index N Niobrara: Meaning and Definition of Find definitions for: Ni•o•brar•a Pronunciation: (nī"u-brâr'u), [key] — n. a river flowing E from E Wyoming through Nebraska to the Missouri. 431 mi. (692 km) long. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: niobrara (Thesaurus) niobous Niort Related Content Daily Word Quiz: secular Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language