/ Dictionary / Index F founderous: Meaning and Definition of Find definitions for: foun•der•ous Pronunciation: (foun'dur-us), [key] — adj. likely to cause foundering; miry; swampy. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. founder effect founders' shares Related Content Daily Word Quiz: procrastinate Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language