What does breastbone mean?
The breastbone is the common name for the sternum, the long, flat bone that runs vertically down the center of the front of the chest. Anchored to the collarbones at its top and joined to most of the ribs along its sides, it completes the protective bony cage around the heart and lungs while also serving as an attachment point for major muscles involved in breathing and arm movement. In everyday speech the word typically surfaces when people describe discomfort or pressure felt behind it — heartburn, anxiety, a strained muscle, or more serious cardiac symptoms. In medicine it takes on a surgical significance: open-heart procedures often involve dividing the breastbone along its length and securing it again with wires as it heals. The term itself is transparently descriptive, combining two plain Old English roots, which makes it one of the more approachable names in human anatomy.
nounThe breastbone is the flat, elongated bone at the front of the chest that connects the ribs and forms the middle part of the rib cage; in formal anatomy it is called the sternum.
- The sternum: the flat bone at the center-front of the chest connecting the ribs.
"The seatbelt pressed hard against her breastbone during the sudden stop."
"A sharp ache settled behind his breastbone after the long run."
"The surgeon made an incision along the patient's breastbone to access the heart."
Plural is regular and typically used when discussing anatomy across individuals or species, e.g. birds' keeled breastbones.
"Flying birds have prominent keels on their breastbones for anchoring powerful flight muscles."
Surgeons can split your breastbone down the middle to reach the heart — and wire it back together like a zipper.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of breastbone
Breastbone is a straightforward compound formed from two native Old English words: "breast" and "bone." Both elements trace back through Proto-Germanic, making the word a purely Germanic formation rather than a borrowing from Latin or Greek. It arose as the everyday English counterpart to "sternum," the learned anatomical term derived from Greek. Related Germanic cognates include German Brustbein, built from exactly the same two elements.
How breastbone is actually used
"Breastbone" is the everyday, non-technical term; "sternum" is preferred in medical and anatomical contexts but both are widely understood. It appears most often in descriptions of chest pain, injury, or surgery.
Easily confused with breastbone
The collarbone (clavicle) is a horizontal bone linking the shoulder to the breastbone, whereas the breastbone (sternum) is the vertical central bone of the chest.