/ Dictionary / Index D Darwinian fitness: Meaning and Definition of Find definitions for: Darwin'ian fit'ness Pronunciation: [key] fitness (def. 3). Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Darwinian Darwinism Related Content Daily Word Quiz: philtrum Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language