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
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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
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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
Around the age of 70, the sacrum and the coccyx may fuse together.
From Textbooks ● Jun. 9, 2022
Thoracic vertebrae have sites for rib attachment, and the vertebrae that give rise to the sacrum and coccyx have fused together into single bones.
From Textbooks ● Jun. 19, 2013
At its inferior, or lower angle, it is united to the coccyx.
From A Treatise on Anatomy, Physiology, and Hygiene (Revised Edition) by Calvin Cutter
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
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