preformation

noun

pre·​for·​ma·​tion ˌprē-fȯr-ˈmā-shən How to pronounce preformation (audio)
1
: previous formation
2
: the now discredited theory that every germ cell contains the organism of its kind fully formed and that development involves merely an increase in size compare epigenesis sense 1, homunculus sense 2
preformationist noun or adjective

Word History

First Known Use

1732, in the meaning defined at sense 1

Time Traveler
The first known use of preformation was in 1732

Dictionary Entries Near preformation

Cite this Entry

“Preformation.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/preformation. Accessed 31 Oct. 2024.

Medical Definition

preformation

noun
pre·​for·​ma·​tion ˌprē-fȯr-ˈmā-shən How to pronounce preformation (audio)
: a now discredited theory in biology that every germ cell contains the organism of its kind fully formed and complete in all its parts and that development involves merely an increase in size from microscopic proportions to those of the adult compare epigenesis
preformationist noun or adjective
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