Which word describes an attitude that lacks modesty or is excessively bold?

The term "audacious" accurately describes an attitude that is excessively bold or daring, often to the point of being disrespectful or lacking in modesty. This word conveys a sense of confidence that can cross the line into brazen or reckless behavior. Individuals who are audacious might take risks that others would avoid due to a lack of humility or restraint. This aligns perfectly with the query regarding an attitude characterized by excessive boldness.

In contrast, "timorous" refers to someone who is shy or lacking confidence, "bashful" indicates a person who is socially awkward or hesitant, and "fearful" describes someone who exhibits a sense of dread or apprehension. Each of these alternatives represents a lack of boldness or assertiveness, which is the opposite of the described attitude. Thus, audacious stands out as the correct choice for describing an excessively bold demeanor.