/ Dictionary / Index D diastasis: Meaning and Definition of Find definitions for: di•as•ta•sis Pronunciation: (dī-as'tu-sis), [key] — pl. -ses the separation of normally joined parts, as in the dislocation of bones, without fracture. the diastolic rest period immediately preceding systole. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: diastasis (Thesaurus) diastase diastatic 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