sternum

American  

[stur-nuhm] / ˈstɜr nəm /

noun

• sterna,
  plural
• sternums
  plural

1. Anatomy, Zoology. a bone or series of bones extending along the middle line of the ventral portion of the body of most vertebrates, consisting in humans of a flat, narrow bone connected with the clavicles and the true ribs; breastbone.

2. the ventral surface of a body segment of an arthropod.

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sternum British  

/ ˈstɜːnəm /

noun

1. Nontechnical name: breastbone.  (in man) a long flat vertical bone, situated in front of the thorax, to which are attached the collarbone and the first seven pairs of ribs

2. the corresponding part in many other vertebrates

3. a cuticular plate covering the ventral surface of a body segment of an arthropod Compare tergum

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sternum Scientific  

/ stûr′nəm /

1. A long, flat bone located in the center of the chest, serving as a support for the collarbone and ribs.

2. Also called breastbone

3. See more at skeleton

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Other Word Forms

Derived Forms

• sternal
  adjective

Inflected Forms

Nouns

• sterna
  plural
• sternums
  plural

Etymology

Origin of sternum

1660–70; < New Latin < Greek stérnon chest, breastbone

Explanation

Your sternum is your breastbone, the flat plate at the top of your rib cage. Mammals and birds — and even arachnids, or spiders — have a sternum. If you study human anatomy, you'll learn that the sternum is a long, flat, T-shaped bone made of fused segments. The rib cage attaches the sternum to the spine, or vertebrae. The word itself comes from the Greek sternon, "chest, breast, or breastbone," from a root that means "flat surface."

Example Sentences

See Examples For:

sternum sterna sternums

I kind of went in head first and it felt like I broke my sternum.

From The Wall Street Journal ● Jun. 22, 2026

One fossil revealed a segmented cartilaginous sternum, along with sternal ribs, intermediate ribs, and connections linking the ribcage to the shoulder girdle.

From Science Daily ● Apr. 23, 2026

Heart surgery is extremely traumatic, physically and emotionally, and requires at least three months of recovery, and many months more for your husband’s sternum to fully heal.

From MarketWatch ● Jan. 22, 2026

But Schlee appeared to take a blow to the sternum on his final run in the third quarter, a 28-yard sprint to Oregon State’s nine-yard line.

From Los Angeles Times ● Oct. 15, 2023

Maybe a broken wing, or sternum, or tail.

From "A Bird Will Soar" by Alison Green Myers

They may be distinguished from the Malacodermata by the presence of only five or six abdominal sterna, while six malpighian tubes are present in some of the families.

From Encyclopaedia Britannica, 11th Edition, Volume 6, Slice 6 "Cockaigne" to "Columbus, Christopher" by Various

No distinct respiratory stigmata behind the sterna of the 1st and 2nd somites of the opisthosoma.

From Encyclopaedia Britannica, 11th Edition, Volume 2, Slice 3 "Apollodorus" to "Aral" by Various

In many genera of the Pentatomidae, bristle-bearing tubercles on the legs are scraped across a set of fine striations on the abdominal sterna.

From Encyclopaedia Britannica, 11th Edition, Volume 13, Slice 3 "Helmont, Jean" to "Hernosand" by Various

Each leg-bearing somite contains a distinct tergum and sternum, the number of sterna never exceeding that of the terga.

From Encyclopaedia Britannica, 11th Edition, Volume 5, Slice 6 "Celtes, Konrad" to "Ceramics" by Various

The first and second abdominal sterna are often suppressed or reduced, on account of the strong development of the hind-legs.

From Encyclopaedia Britannica, 11th Edition, Volume 13, Slice 4 "Hero" to "Hindu Chronology" by Various

Some animals are born with kinked tails and deformed sternums.

From Science Magazine ● Jan. 13, 2022

Dr. Prieto called in a colleague, Katya Valladares, who investigated the skeletons and identified cut marks on many of the children’s sternums.

From New York Times ● Mar. 6, 2019

A line of pale models, their sternums outlined under parchment skin, wound its way around the bare concrete benches, while overhead hung rows of curved and flat translucent panels made from fiberglass and corrugated polycarbonate.

From The Wall Street Journal ● Nov. 5, 2015

They'd gone from cruising to crisis in a heartbeat – and their hearts were beating harder than ever, smashing through their sternums.

From The Guardian ● May 10, 2010

For what on earth—or in air—is the use to me of seeing their boiled sternums and scalped sinciputs, when I'm never shown either how they bear their breasts—or where they carry their heads?

From On the Old Road, Vol. 2 (of 2) A Collection of Miscellaneous Essays and Articles on Art and Literature by John Ruskin