Lamarckism

noun

La·​marck·​ism lə-ˈmär-ˌki-zəm How to pronounce Lamarckism (audio)
: a theory of organic evolution asserting that environmental changes cause structural changes in animals and plants that are transmitted to offspring
Lamarckian adjective

Word History

Etymology

J.-B. de Monet de lamarck + -ism

First Known Use

1884, in the meaning defined above

Time Traveler
The first known use of Lamarckism was in 1884

Browse Nearby Words

Cite this Entry

“Lamarckism.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/Lamarckism. Accessed 6 Jul. 2026.

Kids Definition

Lamarckism

noun
La·​marck·​ism lə-ˈmär-ˌkiz-əm How to pronounce Lamarckism (audio)
: a theory of evolution holding that changes in the environment cause changes in the structure of animals and plants that are passed on to offspring
Lamarckian
-kē-ən
adjective

Medical Definition

Lamarckism

noun
La·​marck·​ism lə-ˈmär-ˌkiz-əm How to pronounce Lamarckism (audio)
: a theory of organic evolution asserting that environmental changes cause structural changes in animals and plants that are transmitted to offspring

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