cranium

American  

[krey-nee-uhm] / ˈkreɪ ni əm /

noun

plural

craniums, crania

1. the skull of a vertebrate.

2. the part of the skull that encloses the brain.

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cranium British  

/ ˈkreɪnɪəm /

noun

1. the skull of a vertebrate

2. Nontechnical name: brainpan.  the part of the skull that encloses the brain

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cranium Scientific  

/ krā′nē-əm /

plural

craniums

1. The vertebrate skull, especially the part that encloses and protects the brain.

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cranium Cultural  

1. The part of the skull that encloses the brain.

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Etymology

Origin of cranium

First recorded in 1375–1425; late Middle English craneum, from Medieval Latin crānium, from Greek krāníon “skull”; akin to kerato-, cerebrum, cornu, horn

Explanation

Your cranium is your skull, the hard bone of your head that protects your brain from injury. Take care of your cranium; it's your built-in helmet! The skull is composed of two primary parts: the cranium, which houses the brain, and the mandible, or jawbone. While the cranium acts as a protective "braincase," it also provides the structural foundation for the facial skeleton. In some animals, the cranium is reinforced so that defensive features, such as horns or antlers, can be anchored directly to the bone. The word comes from the Greek kranion, "upper part of the head," from the root word kara, "head."

Example Sentences

The bumps and contours of the cranium were once believed to reflect the intellectual power and moral strength of the mind inside.

From The Wall Street Journal • Apr. 29, 2026

In vertebrates, where the comparatively large brain is enclosed in a compact cranium, another space-saving mechanism plays a major role: myelination.

From Science Daily • Mar. 6, 2024

The university removed that cranium from the reburial so it can be assessed for return through NAGPRA.

From Seattle Times • Feb. 2, 2024

If the device works as expected, it will answer longstanding questions about the impacts of microgravity inside the cranium.

From New York Times • Nov. 12, 2023

After the shock of rope and teeth, I admit it, I was a bit messed—madmanning it around the house, reeling from room to room, brain gyroscoping inside my cranium.

From "Anthem of a Reluctant Prophet" by Joanne Proulx