/ Dictionary / Index N NPT: Meaning and Definition of Find definitions for: NPT Pronunciation: [key] nonproliferation treaty. n.p.t. Pronunciation: [key] normal pressure and temperature. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. NPR nr. Related Content Daily Word Quiz: ounterfeit Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language