Used 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. "Highbrow" can be applied to music, implying most of the classical music tradition and much of post-bebop jazz; to literature, i.e. literary fiction; to films in the arthouse line; and to comedy that requires significant understanding of analogies or references to appreciate
If you say that a book or discussion is highbrow, you mean that it is intellectual, academic, and is often difficult to understand. He presents his own highbrow literary programme. lowbrow
If you describe someone as highbrow, you mean that they are interested in serious subjects of a very intellectual nature, especially when these are difficult to understand. Highbrow critics sniff that the programme was `too sophisticated' to appeal to most viewers. lowbrow