/ Dictionary / Index D diaster: Meaning and Definition of Find definitions for: di•as•ter Pronunciation: (dī-as'tur), [key] — n. Cell Biol. the stage in mitosis at which the chromosomes, after their division and separation, are grouped near the poles of the spindle. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. diastema diastereomer Related Content Daily Word Quiz: perspicacious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language