Definition of "buttock" [but•tock]

• Either of the two rounded prominences on the human torso that are posterior to the hips and formed by the gluteal muscles and underlying structures. (noun)
• The analogous part of the body on certain mammals. (noun)
• The rear pelvic area of the human body. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "Subject received a flesh wound in the right buttock from the machine gun fire that destroyed the LOH."
• "I swung around for the spot and yanked my sweaty map out from under my left buttock, which is still the best map holder ever devised for a fighter plane, and prepared to get some good coordinates for the rescue guys."
• "The hip-bone, (Os ischium) lies directly under the flank bone, (Os ilium) and is the lowest point of the basin, or pelvis, vulgarly called the buttock, being the point on which we sit."