Most highbrow refers to something that is considered to be sophisticated or intellectual. The antonyms of highbrow can be classified into three broad categories. Firstly, there are words that describe something that is plain, ordinary or simplistic, such as basic, unsophisticated, or straight-forward. Secondly, there are words that describe something that is vulgar, coarse or idiotic, such as lowbrow, ignorant or trashy. Finally, there are words that describe something that is informal or casual, such as relaxed, informal or laid-back. Whatever the antonym, it suggests a departure from the highbrow concepts that require an elevated level of understanding and appreciation.