/ Dictionary / Index D diathesis: Meaning and Definition of Find definitions for: di•ath•e•sis Pronunciation: (dī-ath'u-sis), [key] — pl. -ses a constitutional predisposition or tendency, as to a particular disease or affection. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: diathesis (Thesaurus) diathermy diatom Related Content Daily Word Quiz: portent Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language