coccyx
noun
coc·cyx ˈkäk-siks 
plural coccyges ˈkäk-sə-ˌjēz also coccyxes ˈkäk-sik-səz
also coccyxes ˈkäk-sik-səz : a small bone that articulates with the sacrum and that usually consists of four fused vertebrae which form the terminus of the spinal column in humans and tailless apes
Example Sentences
Recent Examples on the Web These include such otherwise inexplicable ones as the pelvis and leg bones of whales and snakes, the wings of flightless birds, and the human coccyx (tailbone). 
David P. Barash, WSJ, 29 Dec. 2020 The suspension is about as stiff as SUV suspensions get, and although the ride is compliant over most surfaces, hitting a dip will send a coccyx-rattling shudder forward from the rear axle. John Pearley Huffman, Car and Driver, 29 Sep. 2020 And piano-key spines extend from the neck to the coccyx with the ribs flourishing outwards, but often without individual vertebrae, appearing just as a single wobbly line running down the back. Jack Hartnell, Time, 30 Oct. 2019 When necessary, treatment for chronic tailbone pain may include instruction in pelvic floor relaxation techniques; physical therapy; or manipulation of the coccyx, which is usually performed through the rectum. Mayo Clinic, chicagotribune.com, 19 Aug. 2019 Your tailbone, or coccyx, is the bony structure at the bottom of your spine that helps support your pelvic floor. Mayo Clinic, chicagotribune.com, 19 Aug. 2019 The suspension keeps the driver in touch with the road while protecting the coccyx from too many bumps and bruises. John Scott Lewinski, Ars Technica, 8 Apr. 2018 Ab rotation The human spine is composed of five sections: cervical, thoracic, lumbar, sacrum and coccyx. Philly.com, 27 Mar. 2018 See More
David P. Barash, WSJ, 29 Dec. 2020 The suspension is about as stiff as SUV suspensions get, and although the ride is compliant over most surfaces, hitting a dip will send a coccyx-rattling shudder forward from the rear axle. John Pearley Huffman, Car and Driver, 29 Sep. 2020 And piano-key spines extend from the neck to the coccyx with the ribs flourishing outwards, but often without individual vertebrae, appearing just as a single wobbly line running down the back. Jack Hartnell, Time, 30 Oct. 2019 When necessary, treatment for chronic tailbone pain may include instruction in pelvic floor relaxation techniques; physical therapy; or manipulation of the coccyx, which is usually performed through the rectum. Mayo Clinic, chicagotribune.com, 19 Aug. 2019 Your tailbone, or coccyx, is the bony structure at the bottom of your spine that helps support your pelvic floor. Mayo Clinic, chicagotribune.com, 19 Aug. 2019 The suspension keeps the driver in touch with the road while protecting the coccyx from too many bumps and bruises. John Scott Lewinski, Ars Technica, 8 Apr. 2018 Ab rotation The human spine is composed of five sections: cervical, thoracic, lumbar, sacrum and coccyx. Philly.com, 27 Mar. 2018 See More Word History
Etymology
New Latin, from Greek kokkyx cuckoo, coccyx; from its resemblance to a cuckoo's beak
First Known Use
1615, in the meaning defined above
Medical Definition
coccyx
noun
coc·cyx ˈkäk-siks
plural coccyges ˈkäk-sə-ˌjēz also coccyxes ˈkäk-sik-səz
also coccyxes ˈkäk-sik-səz : a small bone that articulates with the sacrum and that usually consists of four fused vertebrae which form the terminus of the spinal column