coccyx
Americannoun
plural
coccyges-
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
plural
coccyges-
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
Other Word Forms
- coccygeal adjective
- intercoccygeal adjective
- precoccygeal adjective
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.
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
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
Our coccyx is a vestige of the tail of animals.
From The Sexual Question A Scientific, psychological, hygienic and sociological study by Forel, Auguste
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.
