The definition for diffident is "Lacking self–confidence." Used in a sentence: The diffident student never raised her hand in class, even when she knew the answer.

The definition for fraud is "Trick." Used in a sentence: The con man's fraud involved selling swampland to gullible investors.

The definition for immoderate is "Beyond usual or proper limits." Used in a sentence: Bob's immoderate appetite shocked the guests at the wedding banquet.

The definition for naive is "Lacking worldy wisdom." Used in a sentence: The naive Simon assumed that everyone was as simple and kind as he was.

The definition for servile is "Fearfully submissive." Used in a sentence: Felicia's servile attitude annoyed her boss, who preferred an assistant with more backbone.