The definition for corroborate is "To support with evidence." Used in a sentence: "Unless you can corroborate your story, it will not be admissible in court," the attorney told his client.

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 euphoria is "Feeling of great happiness." Used in a sentence: Cassandra was overcome with euphoria when she met her long–lost sister.

The definition for extant is "Currently existing." Used in a sentence: Some consider Clint Eastwood the greatest extant American director.

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.