/ Dictionary / Index N NSU: Meaning and Definition of Find definitions for: NSU Pronunciation: [key] nonspecific urethritis. See Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: nsu (Thesaurus) n.s.p.f. N.S.W. Related Content Daily Word Quiz: careening Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language