coccyx
Americannoun
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coccyges
plural
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a small triangular bone forming the lower extremity of the spinal column in humans, consisting of four ankylosed rudimentary vertebrae.
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a corresponding part in certain animals.
noun
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coccyges
plural
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A small triangular bone at the base of the spine in humans and apes. It is composed of several fused vertebrae.
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Also called tailbone
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Derived Forms
Inflected Forms
Nouns
Etymology
Origin of coccyx
1605–15; < New Latin < Greek kókkyx cuckoo, from its resemblance to a cuckoo's beak
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Vocabulary lists containing coccyx
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
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The boy was fifteen, skinny, almost malnourished, so that the hip bones and coccyx stood out sharply.
From The Wall Street Journal ● Nov. 11, 2025
Following this evolutionary split, the group of apes that includes present-day humans evolved the formation of fewer tail vertebrae, giving rise to the coccyx, or tailbone.
From Science Daily ● Feb. 28, 2024
The vertebral column originally develops as 33 vertebrae, but is eventually reduced to 24 vertebrae, plus the sacrum and coccyx.
From Textbooks ● Jun. 19, 2013
In the adult, this fetal curvature is retained in two regions of the vertebral column as the thoracic curve, which involves the thoracic vertebrae, and the sacrococcygeal curve, formed by the sacrum and coccyx.
From Textbooks ● Jun. 19, 2013
Next, go with the P. P. to coccyx two or three minutes; continuing, as at first, to manipulate with N. P. over the liver.
From A Newly Discovered System of Electrical Medication by Daniel Clark
They are joined at the coccyges and sacra, and the spinal columns have nearly the same axis.
From Essays In Pastoral Medicine by Austin ?Malley
The twins are joined only by the latero-posterior aspects of the sacra and coccyges, so that the two individuals are placed almost back to back.
From Essays In Pastoral Medicine by Austin ?Malley
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
