/ Dictionary / Index O Origin of Species, The*: Meaning and Definition of Find definitions for: Or'igin of Spe'cies The Pronunciation: [key] (On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life) a treatise (1859) by Charles Darwin setting forth his theory of evolution. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. originative orihon Related Content Daily Word Quiz: penchant Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language