/ Dictionary / Index P propositus: Meaning and Definition of Find definitions for: pro•pos•i•tus Pronunciation: (pru-poz'i-tus), [key] — pl. -ti the person from whom a line of descent is derived on a genealogical table. proband. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: propositus (Thesaurus) propositional function propound Related Content Daily Word Quiz: mamba Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language