What does 'diffident' imply about a person's level of self-confidence?

The term "diffident" is used to describe a person who is shy or lacking in self-confidence. This suggests that an individual who is diffident tends to hold back or feel uncertain about their abilities or worth, leading them to appear reserved or hesitant in social situations. The essence of the word captures a sense of timidity or self-doubt rather than confidence, making "lacking" the most accurate choice.

In contrast, options like "overconfident," "average," and "excessive" convey a sense of positive self-assurance or balance that is not present in the meaning of "diffident." Therefore, "lacking" correctly encapsulates the essence of the word, highlighting a deficit in self-confidence.