Middlebrow is a term often used to describe someone or something that is considered intellectually or culturally mediocre. However, there are a number of synonyms that can be used to describe this concept, including common, ordinary, mainstream, pedestrian, and average. Common is a more neutral term, while ordinary and mainstream have connotations of customary or conventional. Pedestrian emphasizes a lack of creativity or originality, while average suggests something common or typical. Other synonyms for middlebrow include bland, unimaginative, and unexceptional. Overall, these words all convey a sense of mediocrity or lack of intellectual depth.