What term describes someone who is overly self-important in speech and manner?

The term that describes someone who is overly self-important in speech and manner is "pompous." This word conveys a sense of arrogance and inflated self-esteem, often evidenced by a grandiose way of speaking or behaving that is meant to impress others. A pompous person usually considers themselves superior and may express that superiority through their language and demeanor, leading to an impression of self-importance.

In contrast, modest refers to someone who is unassuming and tends to downplay their own achievements or importance. Reserved describes a person who is restrained in their expression of emotions or opinions, and humble indicates a lack of arrogance or an awareness of one's limitations and modesty about one's own worth. These terms do not capture the essence of inflated self-importance that defines pompous behavior.