ter·​a·​tol·​o·​gy ˌter-ə-ˈtä-lə-jē How to pronounce teratology (audio)
: the study of malformations or serious deviations from the normal type in developing organisms
teratologist noun

Word History


borrowed from French tératologie, from Greek terat-, téras "sign sent by the gods, portent, marvel, monster" + French -o- -o- + -logie -logy — more at terato-

Note: As a term in the life sciences introduced by the French zoologist Isidore Geoffroy Saint-Hilaire (1805-61) in "De la nécessité et des moyens de créer pour les Monstres une nomenclature rationelle et méthodique," Annales des sciences naturelles, tome 20 (1830), p. 326. It is uncertain if Geoffroy Saint-Hilaire was aware of the ancient Greek word teratología "account of marvelous things, marvelous tales," formed from the same elements but with an entirely different sense.

First Known Use

circa 1842, in the meaning defined above

Time Traveler
The first known use of teratology was circa 1842

Dictionary Entries Near teratology

Cite this Entry

“Teratology.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/teratology. Accessed 24 May. 2024.

Medical Definition


ter·​a·​tol·​o·​gy ˌter-ə-ˈtäl-ə-jē How to pronounce teratology (audio)
plural teratologies
: the study of malformations or serious deviations from the normal type in organisms

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