/ Dictionary / Index N ninhydrin: Meaning and Definition of Find definitions for: nin•hy•drin Pronunciation: (nin-hī'drin), [key] — n. Chem. a white or yellow, toxic, crystalline or powdery compound, CHO&multiplydot;HO, that reddens when heated above 100°C, a monohydrate, soluble in water or alcohol: used primarily as a reagent to detect the presence of various amino acids. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Ningxia Hui Ninib Related Content Daily Word Quiz: eureka Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language