flat top of the cranium
Anatomical term referring to the flat upper surface of the skull.
解剖学の授業で、頭の皿の構造について学んだ。
In anatomy class, we learned about the structure of the flat top of the cranium.
plate-like depression on a kappa's head
Refers to the dish-shaped hollow on top of a kappa's head, which holds water and is central to kappa folklore.
See also: 河童
河童の頭の皿が乾くと、力が出せなくなるという。
It is said that when the plate on a kappa's head dries out, it loses its strength.
Compound of 頭 (atama, 'head') + の (possessive particle) + 皿 (sara, 'plate, dish'). The anatomical sense is a straightforward descriptive term; the kappa sense derives from the creature's distinctive head feature in Japanese folklore.