/ Dictionary / Index L Lamarck: Meaning and Definition of Find definitions for: La•marck Pronunciation: (lu-märk' Fr. la-mark'), [key] 1744–1829, French naturalist: pioneer in the field of comparative anatomy. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: lamarck (Thesaurus) Lamar Lamarckian Related Content Daily Word Quiz: inutiae Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language