/ Dictionary / Index C chromatin: Meaning and Definition of Find definitions for: chro•ma•tin Pronunciation: (krō'mu-tin), [key] — n. Cell Biol. the readily stainable substance of a cell nucleus, consisting of DNA, RNA, and various proteins, that forms chromosomes during cell division. See diag. under Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: chromatin (Thesaurus) chromatid chromatism Related Content Daily Word Quiz: lunar Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language