Skullcap (noun)

1. A small close-fitting cap worn on the head, often made of cloth or leather, and typically worn for protection or warmth.
2. A small cup-shaped structure that covers the top of the skull.

Origin:

From skull + cap.

Examples:

1. The rider wore a leather skullcap to protect his head from injury.
2. Skullcaps are often worn for religious or cultural reasons.
3. The skullcap is a small bony structure that sits on top of the skull.
4. The skullcap is also known as calvaria or calvarium.
5. The skullcap is an important structure in neurosurgery as it protects the brain.