corroborate
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.
corrosive
The definition for corrosive is "Bitingly sarcastic." Used in a sentence: The cruel Estella's corrosive comments made Pip cry.
extant
The definition for extant is "Currently existing." Used in a sentence: Some consider Clint Eastwood the greatest extant American director.
immoderate
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.
mediate
The definition for mediate is "To come between parties in order to reconcile." Used in a sentence: The diplomatic Henry was able to mediate between the quarreling sisters.