/ Dictionary / Index F founder effect: Meaning and Definition of Find definitions for: found'er effect" Pronunciation: [key] — Biol. Biol. the accumulation of random genetic changes in an isolated population as a result of its proliferation from only a few parent colonizers. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. founder founderous 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