Used colloquially as a noun or adjective, "highbrow" is synonymous with intellectual; as an adjective, it also means elite, and generally carries a connotation of high culture. The word draws its metonymy from the pseudoscience of phrenology

, and was originally simply a physical descriptor.

What is the word highbrow mean?

: a person who possesses or has pretensions to superior learning or culture.

Is highbrow informal?

Informal. Appealing to or engaging the intellect: cerebral, intellectual, sophisticated, thoughtful.