Definition of "sternum" [ster•num]

• A long flat bone in most vertebrates that is situated along the ventral midline of the thorax and articulates with the ribs. The manubrium of the sternum articulates with the clavicles in humans and certain other vertebrates. Also called breastbone. (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.

• "Others may have weighed whether to wear a polo, V-neck, scoop neck or button-down if lanyard chafing around the neck or on the sternum is a concern."
• "Admittedly, the sternum is a tough one, but if you can break a cinderblock with the heel of your hand, you can probably crack somebody's sternum, and if This Person were really so knowledgable about assassins and fighting, s/he would know that."
• "The sternum is the breastbone, and the keel is where wing muscles normally attach."