The definition for epistolary is "Contained or carried on in letters." Used in a sentence: The shoebox filled with letters was the ony remains of Ming's epistolary friendship with Emile.

The definition for gruff is "Rough or stern in manner or speech." Used in a sentence: Heidi's grandfather was gruff, barking stern orders and hardly smiling.

The definition for incumbent is "Necessary as a duty or responsibility." Used in a sentence: It was incumbent on Jack to attend his father's retirement party.

The definition for precept is "A general rule of action." Used in a sentence: All the students know Mrs. Brown's strict precept; no talking in class.

The definition for turmoil is "Extreme confusion, agitation." Used in a sentence: The windstorm caused such turmoil in the lake that the sailboat capsized.