Egghead

Noun / UK Slang

Egghead refers to someone who is very clever or intellectually focused. It can also be used to describe someone who is bald, due to the resemblance of a bald head to an egg.

Example: “Tom’s such an egghead, always getting top marks in class.”
Means: “Tom’s very clever, always getting top marks in class.”

Example: “He’s been called egghead ever since he shaved his head.”
Means: “He’s been called bald ever since he shaved his head.”